Year	constant 2015 US$
1991	31596.6645714552
1992	27380.593984889885
1993	32184.402849141432
1994	31555.95494035379
1995	34636.09642779402
1996	37538.4553992639
1997	40842.51162303278
1998	39778.02466146717
1999	37222.645821867925
2000	40970.810274107316
2001	37436.07817965661
2002	37273.31235622495
2003	43569.394553060054
2004	44091.00875872249
2005	47664.73563965756
2006	46553.878375825014
2007	39202.67392060873
2008	43694.194599228475
2009	47631.13156487035
2010	42168.54561072874
2011	46315.79307446429
2012	49509.22017347954
2013	51136.58264895306
2014	53436.1924010234
2015	54292.87748355694
2016	48387.07751484038
2017	46678.21012636177
2018	52169.83044759041
2019	50833.90545315863
2020	50023.354993737805
2021	48488.92595129862
2022	49776.347050620956