Year	Percent
1991	28.559
1992	29.204
1993	29.543
1994	29.84
1995	31.171
1996	32.387
1997	33.35
1998	35.261
1999	35.743
2000	36.977
2001	36.727
2002	37.495
2003	37.727
2004	38.154
2005	38.607
2006	38.844
2007	39.453
2008	39.653
2009	40.712
2010	41.299
2011	41.733
2012	42.041
2013	42.942
2014	43.068
2015	43.921
2016	44.317
2017	44.928
2018	45.348
2019	45.761
2020	46.308
2021	46.942
2022	47.345