Year	% net
1971	5.42747
1991	7.03939
2008	33.66288
2009	34.86349
2010	36.47297
2011	37.7848
2013	37.13579
2014	40.07741
2015	34.93344
2016	37.22141
2017	32.47233
2018	32.95999