Year	% of total primary
1996	1.23053002357483
1999	1.31521999835968
2000	1.31436002254486
2001	1.77850997447968
2002	1.86952996253967
2003	1.86181998252869
2004	1.97180998325348
2005	2.04116988182068
2006	2.62849998474121
2007	2.76483988761902
2008	3.04305005073547
2009	3.96123003959656
2010	4.07237005233765
2011	4.18868017196655
2012	4.46740007400513
2013	4.78557014465332
2014	5.43159008026123
2015	5.92884016036987
2016	4.74982976913452
2017	5.36575984954834
2018	5.84743976593018
2019	6.41388988494873
2020	6.76684999465942
2021	7.07034015655518
2022	7.36745023727417