Year	PPG (TDS, current US$)
1970	3399100
1971	4221669.6
1972	8624451.9
1973	9710547.7
1974	4359784.7
1975	3350569.4
1976	1963276.4
1977	2177789.7
1978	3843596
1979	7198602.5
1980	15999023.2
1981	18676350.2
1982	20542354.9
1983	20384034.6
1984	18687759.7
1985	23533657.9
1986	27910091.1
1987	43217254.3
1988	32485782.8
1989	29356525.9
1990	43429857.8
1991	25546514.7
1992	21332644.7
1993	20847033.2
1994	22859306.9
1995	17629637.3
1996	29373334.8
1997	20546170.6
1998	25888689.2
1999	32993375.1
2000	29636601.5
2001	25105028.8
2002	20763647.7
2003	31058899
2004	45993899.1
2005	35298062
2006	40223870.5
2007	51365337.6
2008	59026410.1
2009	55100328
2010	51277836.8
2011	48457919.5
2012	45613460.8
2013	37187287.6
2014	34133103.9
2015	33872426.8
2016	39647737.7
2017	45727429.4
2018	47030115.4
2019	53153312.6
2020	59093219.7
2021	63464655.3
2022	53410798.1