Year	PPG (TDS, current US$)
1970	259000
1971	415137.8
1972	644305.5
1973	655810.4
1974	737549.7
1975	819361.9
1976	1482114.3
1977	622375.5
1978	1117410.9
1979	690958.4
1980	1378140.6
1981	982216.9
1982	1290590.6
1983	4099238.5
1984	3505897.8
1985	3349719.4
1986	4243074.7
1987	4911158.3
1988	6021499.7
1989	3482505.6
1990	3281218.5
1991	3613046
1992	6118177
1993	7692871.1
1994	8140189.4
1995	7470124.9
1996	7547447.8
1997	6919237.1
1998	9702583.6
1999	9590721.6
2000	13521434.6
2001	15979737.9
2002	27341086.7
2003	30240979.6
2004	27406012.4
2005	8981094.1
2006	12191984.8
2007	15340344.2
2008	16979118.1
2009	20012060
2010	25640884.1
2011	24663192.4
2012	14112636.4
2013	22052662.9
2014	18039713.1
2015	22269003.3
2016	46801638.6
2017	54784076.1
2018	50698919.2
2019	51216960.1
2020	44299800.2
2021	45731721.1
2022	46256528.2