Year	US Dollars adjusted for inflation)
1991	1143.268
1992	1115.767
1993	1108.118
1994	1094.74
1995	1097.591
1996	1112.368
1997	1143.488
1998	1162.884
1999	1186.513
2000	1193.971
2001	1216.957
2002	1257.797
2003	1248.646
2004	1252.958
2005	1264.421
2006	1269.36
2007	1264.337
2008	1296.309
2009	1261.127
2010	1255.943
2011	1275.788
2012	1295.483
2013	1292.956
2014	1265.417
2015	1233.56
2016	1265.007
2017	1308.598
2018	1360.993
2019	1417.654
2020	1477.447
2021	1509.073
2022	1543.801