**********************************************************************
*** Monthly Estimates of C-13/C-12 (per mil) in Fossil-Fuel        ***
*** Carbon Dioxide Emissions from the U.S.A.                       ***
*** Source: T.J. Blasing (1)                                       ***
***              Christine Broniak (2)	                           ***
***              Gregg Marland (1)                                 ***
***                                                                ***  
***              (1)Carbon Dioxide Information Analysis Center     ***
***              Oak Ridge National Laboratory                     ***
***              Oak Ridge, Tennessee 37831-6335                   ***
***                                                                *** 
***              (2)Department of Agricultural &                   ***
***              Resource Economics                                ***
***              Oregon State University                           ***
***              Corvallis, Oregon 97331-3601                      ***
*** July 2004                                                      ***
***                                                                ***
**********************************************************************

Dates are given as month and year (e.g., Jan -81)

Month		delta C-13
Jan-81		-30.46685902
Feb-81		-30.36225259
Mar-81		-30.32479961
Apr-81		-29.77594623
May-81		-29.59183078
Jun-81		-29.16711557
Jul-81		-28.95722016
Aug-81		-29.03125789
Sep-81		-29.10604979
Oct-81		-29.62259377
Nov-81		-29.90806709
Dec-81		-30.3950176
Jan-82		-30.87117693
Feb-82		-30.62065506
Mar-82		-30.29451363
Apr-82		-29.73119267
May-82		-28.96169634
Jun-82		-28.91461247
Jul-82		-28.75917604
Aug-82		-28.77284365
Sep-82		-28.96760913
Oct-82		-29.3984346
Nov-82		-29.91167219
Dec-82		-30.06518236
Jan-83		-30.95603583
Feb-83		-30.71505476
Mar-83		-30.21204912
Apr-83		-29.92650969
May-83		-29.25063758
Jun-83		-28.71282149
Jul-83		-28.40704716
Aug-83		-28.38702237
Sep-83		-28.51060243
Oct-83		-28.73286902
Nov-83		-29.14618114
Dec-83		-29.48173803
Jan-84		-30.64910118
Feb-84		-30.52292783
Mar-84		-30.06434764
Apr-84		-29.87776657
May-84		-29.27038572
Jun-84		-28.74029979
Jul-84		-28.58041326
Aug-84		-28.47535695
Sep-84		-28.62667979
Oct-84		-28.78188356
Nov-84		-29.27239733
Dec-84		-29.84309108
Jan-85		-30.26681454
Feb-85		-30.78816876
Mar-85		-29.94016408
Apr-85		-29.50587447
May-85		-28.71769544
Jun-85		-28.54152737
Jul-85		-28.44708098
Aug-85		-28.4264227
Sep-85		-28.49265471
Oct-85		-28.69844553
Nov-85		-29.12879001
Dec-85		-29.88570442
Jan-86		-30.33938057
Feb-86		-30.28163183
Mar-86		-29.86286762
Apr-86		-29.31438705
May-86		-28.79438222
Jun-86		-28.35894267
Jul-86		-28.11405488
Aug-86		-28.15121169
Sep-86		-28.21246248
Oct-86		-28.38170427
Nov-86		-28.9426442
Dec-86		-29.54314012
Jan-87		-30.31588927
Feb-87		-30.36116746
Mar-87		-29.93835054
Apr-87		-29.40103192
May-87		-28.72843799
Jun-87		-28.37114576
Jul-87		-28.14471633
Aug-87		-28.26069121
Sep-87		-28.335906
Oct-87		-28.72539396
Nov-87		-29.2353569
Dec-87		-29.64679737
Jan-88		-30.18341244
Feb-88		-30.18207021
Mar-88		-29.86698881
Apr-88		-29.37484094
May-88		-28.97793201
Jun-88		-28.4641834
Jul-88		-28.31831833
Aug-88		-28.31222661
Sep-88		-28.39776158
Oct-88		-28.64381331
Nov-88		-29.13070292
Dec-88		-29.51279462
Jan-89		-29.98415102
Feb-89		-30.15226713
Mar-89		-29.90826017
Apr-89		-29.56620166
May-89		-29.00930728
Jun-89		-28.54866359
Jul-89		-28.48697602
Aug-89		-28.42154522
Sep-89		-28.58320065
Oct-89		-28.87703457
Nov-89		-29.35189491
Dec-89		-29.89556631
Jan-90		-30.18970347
Feb-90		-30.04115214
Mar-90		-29.75452774
Apr-90		-29.55385564
May-90		-29.02761288
Jun-90		-28.67465192
Jul-90		-28.49763014
Aug-90		-28.46576367
Sep-90		-28.66415537
Oct-90		-28.90806863
Nov-90		-29.35940449
Dec-90		-29.87483897
Jan-91		-30.36452626
Feb-91		-30.28779741
Mar-91		-29.97110521
Apr-91		-29.59433152
May-91		-28.96881194
Jun-91		-28.55530141
Jul-91		-28.56088525
Aug-91		-28.52413775
Sep-91		-28.66115485
Oct-91		-29.04319315
Nov-91		-29.58011496
Dec-91		-29.85113348
Jan-92		-30.347837
Feb-92		-30.35144779
Mar-92		-29.97761624
Apr-92		-29.72550972
May-92		-29.13437181
Jun-92		-28.74581524
Jul-92		-28.56389225
Aug-92		-28.54912132
Sep-92		-28.65988961
Oct-92		-28.89818511
Nov-92		-29.57551959
Dec-92		-30.05320778
Jan-93		-30.47934
Feb-93		-30.4911383
Mar-93		-30.17541505
Apr-93		-29.68244721
May-93		-28.8780573
Jun-93		-28.67832725
Jul-93		-28.52697237
Aug-93		-28.57929236
Sep-93		-28.65813176
Oct-93		-29.10260508
Nov-93		-29.60659155
Dec-93		-29.97876063
Jan-94		-30.59236205
Feb-94		-30.65768891
Mar-94		-30.14861876
Apr-94		-29.61662636
May-94		-29.04350534
Jun-94		-28.77875899
Jul-94		-28.68872168
Aug-94		-28.72212144
Sep-94		-28.89865956
Oct-94		-29.12354011
Nov-94		-29.72190393
Dec-94		-30.080478
Jan-95		-30.62268858
Feb-95		-30.58620159
Mar-95		-30.30282427
Apr-95		-29.977902
May-95		-29.41810361
Jun-95		-28.88925445
Jul-95		-28.8834831
Aug-95		-28.84428634
Sep-95		-28.90851103
Oct-95		-29.12574782
Nov-95		-29.86147239
Dec-95		-30.32220059
Jan-96		-30.64017811
Feb-96		-30.54810269
Mar-96		-30.2865485
Apr-96		-29.91117728
May-96		-29.26926105
Jun-96		-28.91967834
Jul-96		-28.69788752
Aug-96		-28.71280267
Sep-96		-28.87803202
Oct-96		-29.00702962
Nov-96		-29.69129083
Dec-96		-30.15226006
Jan-97		-30.45800018
Feb-97		-30.56838412
Mar-97		-30.18480662
Apr-97		-29.7525049
May-97		-29.27183508
Jun-97		-28.90412324
Jul-97		-28.78334872
Aug-97		-28.82717789
Sep-97		-28.84866285
Oct-97		-28.9472596
Nov-97		-29.70783193
Dec-97		-30.13724863
Jan-98		-30.42348815
Feb-98		-30.37700396
Mar-98		-30.14166866
Apr-98		-29.56036295
May-98		-29.03558443
Jun-98		-28.82217902
Jul-98		-28.82201097
Aug-98		-28.84772383
Sep-98		-28.87018255
Oct-98		-28.93577863
Nov-98		-29.53131324
Dec-98		-29.94786194
Jan-99		-30.51730797
Feb-99		-30.32073035
Mar-99		-30.1235093
Apr-99		-29.6487909
May-99		-29.02097207
Jun-99		-28.71697726
Jul-99		-28.66755534
Aug-99		-28.78322001
Sep-99		-28.82567628
Oct-99		-29.05347695
Nov-99		-29.42188434
Dec-99		-29.93202504
Jan-00		-30.38634677
Feb-00		-30.35267307
Mar-00		-29.87548894
Apr-00		-29.65420833
May-00		-29.13746288
Jun-00		-28.7811324
Jul-00		-28.70160627
Aug-00		-28.80932602
Sep-00		-28.74254785
Oct-00		-28.8961107
Nov-00		-29.57680651
Dec-00		-30.27820955
Jan-01		-30.34775253
Feb-01		-30.30012678
Mar-01		-29.97801751
Apr-01		-29.51868237
May-01		-28.84250598
Jun-01		-28.62979881
Jul-01		-28.68576343
Aug-01		-28.76235448
Sep-01		-28.83047997
Oct-01		-29.10328722
Nov-01		-29.30239625
Dec-01		-29.81799998
Jan-02		-30.28775426
Feb-02		-30.34721208
Mar-02		-30.09205644
Apr-02		-29.63413912
May-02		-29.01188415
Jun-02		-28.86198033
Jul-02		-28.91365133
Aug-02		-28.88212184
Sep-02		-28.78312571
Oct-02		-28.96975887
Nov-02		-29.47218014
Dec-02		-29.97330018
Jan-03		-30.30580476
Feb-03		-30.42378892
Mar-03		-29.85595092
Apr-03		-29.30033136
May-03		-28.80278247
Jun-03		-28.39327093
Jul-03		-28.57828775
Aug-03		-28.5974811
Sep-03		-28.46086511
Oct-03		-28.74269439
Nov-03		-29.1185171
Dec-03		-29.67357613