Year	constant 2015 US$
1991	7232.702362784974
1992	9527.511318098996
1993	12476.16319887026
1994	11284.263605987913
1995	9473.072807388178
1996	11166.54131772008
1997	10211.22041637912
1998	10752.955609906698
1999	12659.237359972612
2000	13366.00567444134
2001	13150.867049360253
2002	12347.686655813559
2003	8048.724263650052
2004	14138.93059250774
2005	14328.144562888372
2006	14946.427999530435
2007	14834.980806040594
2008	15308.249986465755
2009	15071.52659926013
2010	15776.022347658494
2011	16283.062020375693
2012	17746.38559812985
2013	18180.22045726019
2014	16631.782661150137
2015	15538.658363314993
2016	15002.688824725019
2017	16094.457189973318
2018	17274.016458684462
2019	16789.66696780679
2020	16251.223501549526
2021	16764.604743217726
2022	16257.037838437313
