Year	Percent
1991	10.202
1992	10.518
1993	10.67
1994	11.025
1995	11.338
1996	11.577
1997	11.896
1998	12.722
1999	13.42
2000	14.293
2001	14.912
2002	15.652
2003	17.011
2004	18.31
2005	19.703
2006	21.327
2007	22.545
2008	23.887
2009	25.392
2010	26.606
2011	27.941
2012	29.602
2013	31.472
2014	33.284
2015	35.244
2016	36.268
2017	37.611
2018	39.264
2019	40.853
2020	42.38
2021	43.916
2022	45.18
