Data digitised from Fig 4 of doi: 10.1073/pnas.022055499

Year (Ga)	pCO2 Ratio
-490.353697749  1.53713134578
-454.98392283  2.88677244578
-445.337620579  2.66997138762
-435.048231511  2.88002501508
-425.40192926  1.95754409461
-415.112540193  1.68911235203
-394.855305466  1.77186799564
-385.530546624  2.3261490611
-375.241157556  2.59472248203
-365.273311897  2.26776873226
-354.98392283  2.92876900344
-345.01607717  2.80147101959
-304.823151125  2.26130023078
-264.951768489  3.84505149675
-255.305466238  3.81069450056
-245.01607717  3.16016293009
-225.080385852  2.57165990558
-194.855305466  2.2964807323
-184.887459807  3.33269393606
-165.273311897  3.35692535876
-154.98392283  2.77524060413
-143.408360129  2.49993303485
-137.942122186  2.11787084027
-133.118971061  2.0490572303
-128.295819936  1.94237787162
-118.327974277  2.46223995661
-104.180064309  2.0320447615
-93.5691318328  1.89786652351
-89.3890675241  2.05968531914
-87.459807074  1.72579154468
-84.8874598071  1.68105882418
-78.4565916399  1.94272099883
-69.4533762058  1.66739571976
-62.7009646302  1.87398265547
-58.5209003215  1.96695463526
-53.3762057878  1.99797112197
-44.0514469453  1.9016497778
-36.9774919614  1.81563995993
-32.154340836  1.86730827767
-26.3665594855  1.51967170473
-19.61414791  1.37858222048
-13.1832797428  1.20306711458
-7.71704180064  1.15835431759
-3.2154340836  1.06199976756
-0.64308681672  1.00694002468