Year constant 2015 US$ 1991 4870.925958391998 1992 5441.41082053777 1993 5021.57290577114 1994 6015.577030005192 1995 5799.529003112901 1996 5454.113770016859 1997 6070.782917932141 1998 6370.8522460703125 1999 6473.6476733953605 2000 6730.029249660628 2001 6394.8479303041 2002 6593.747685151858 2003 6939.176824137783 2004 7680.6674509172435 2005 8256.403340737073 2006 8707.965373665453 2007 9077.756147273361 2008 9695.810955264129 2009 9676.432862791353 2010 9453.030939011574 2011 10327.159410140664 2012 11780.304976534588 2013 11941.2708054235 2014 12251.723122983596 2015 12350.347664387667 2016 12534.094141633384 2017 13089.031083315615 2018 13812.318899096686 2019 13832.405892580671 2020 14339.789256119187 2021 14413.942715803387 2022 13864.723984842884