Year	% of total primary
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1977	0
1978	0
1979	0
1980	0
1981	0
1982	0
1983	0
1984	0
1985	0
1986	0
1987	0
1988	0
1989	0
1990	0
1991	0
1992	0
1996	0.266869992017746
1997	0.273739993572235
1999	0.345860004425049
2000	0.323000013828278
2001	0.310400009155273
2002	0.345239996910095
2003	0.373560011386871
2004	0.380309998989105
2005	0.444110006093979
2007	0.546370029449463
2008	0.633419990539551
2009	0.737529993057251
2010	0.764769971370697
2011	0.737789988517761
2012	0.754840016365051
2013	0.792750000953674
2014	0.796239972114563
2015	0.91636997461319
2016	1.09172999858856
2017	1.29753005504608
2018	1.47868001461029
2019	1.67096996307373
2020	1.87232995033264
2021	2.05142998695374