Year	constant 2015 US$
1978	17414213.55299578
1979	19126403.172404647
1980	24367354.805364195
1981	19021985.328706663
1982	19690171.85596112
1983	21611162.093800858
1984	21757312.00601297
1985	23594785.50337692
1986	24847606.748444814
1987	27896134.35339749
1988	30819395.614877637
1989	31717248.794819996
1990	40069378.7389511
1991	47252224.773951024
1992	49716098.32720094
1993	47210453.218404174
1994	45665314.04429969
1995	50822752.84838604
1996	58464963.947976075
1997	74960437.1460075
1998	87697449.16308422
1999	70074435.66609383
2000	95020941.47882423
2001	92075288.39067204
2002	94745472.20127596
2003	83944478.43953878
2004	76557375.90117595
2005	85398645.85533439
2006	88174036.4236239
2007	91250377.95550342
2008	79974106.3457373
2009	70971240.62680139
2010	76959618.34939875
2011	82330446.01708682
2012	102347357.2848733
2013	88960533.10364509
2014	83338946.45787293
2015	83916005.23512037
2016	97316693.23106404
2017	98696893.15908946
2018	106334830.45540307
2019	84478608.53474724
2020	99271462.74198432
2021	110765875.14094472
2022	98814112.17335537
2023	97111010.58312634