Year	% net
1977	6.56129
1981	6.23566
1998	40.60347
1999	44.85033
2000	47.09899
2001	49.58639
2002	51.17523
2003	51.04549
2004	45.94321
2005	45.41747
2006	45.90001
2007	46.63704
2009	48.25183
2010	50.41391
2011	50.83343
2012	53.12643
2013	56.53654
2015	63.11644
2016	68.92778
2017	68.87605
2018	72.27917