Year	% net
1977	39.38276
1996	46.8227
1997	47.69157
1999	48.64547
2000	47.3909
2001	51.25323
2002	50.44859
2003	49.87982
2009	50.48391
2013	64.17623
2014	67.64352
2015	72.05407
2016	79.03977
2017	81.9408
2018	86.60521