Year	% of total primary
1971	3.28665995597839
1972	1.51314997673035
1973	2.38858008384705
1999	1.57129001617432
2000	1.61784994602203
2001	0.947409987449646
2002	0.851870000362396
2003	0.891089975833893
2004	0.571940004825592
2005	0.491320013999939
2006	0.921019971370697
2007	0.7464399933815
2008	1.26031005382538
2009	1.17588996887207
2010	1.4026700258255
2011	1.48701000213623
2012	2.38081002235413
2013	2.27546000480652
2014	2.57784008979797
2015	3.38672995567322
2016	4.52204990386963
2017	4.24174022674561
2018	5.20640993118286
2019	5.68090009689331