Year	% of total primary
1971	0
1972	0
1973	0
1974	0
1975	0
1976	0
1982	0
1983	0
1984	0
1985	0
1987	0
1988	0
1989	0
1990	0
1995	0
1998	0.261830002069473
1999	0.475989997386932
2000	0.922900021076202
2001	2.21732997894287
2002	2.29257011413574
2003	2.48746991157532
2004	2.92028999328613
2005	3.17908000946045
2007	5.02921009063721
2008	5.2982702255249
2009	5.27940988540649
2010	4.92981004714966
2011	4.96990013122559
2012	5.26689004898071
2013	5.37681007385254
2014	5.73615980148315
2015	5.82515001296997
2016	5.58205986022949
2017	5.51711988449097
2018	5.79336023330688
2019	6.37119007110596