Year	PPG (TDS, current US$)
1981	491746.1
1982	477519
1983	559073
1984	570400.5
1985	555773.5
1986	958856.9
1987	2618772.6
1988	1287095.3
1989	1259346.6
1990	1694401.9
1991	1188714
1992	1432515
1993	1396683.8
1994	1352296
1995	1310234.2
1996	1339025.7
1997	1147240.6
1998	897496.2
1999	1340127.7
2000	1531702.2
2001	1464742.1
2002	1575301
2003	1790741.5
2004	2417699.2
2005	1810277
2006	3124793.6
2007	3025328.1
2008	3668889.4
2009	4908772.8
2010	5163516.4
2011	4893216.5
2012	4832201.6
2013	6317613.1
2014	6977639.2
2015	6288512.3
2016	8050409.4
2017	8534259
2018	16200447.5
2019	8983649.6
2020	14448157.3
2021	16938867.7
2022	20393142.3