Year	Percent
1991	30.19
1992	27.951
1993	29.154
1994	26.79
1995	28.363
1996	28.281
1997	30.258
1998	29.995
1999	31.674
2000	30.124
2001	30.359
2002	30.895
2003	35.181
2004	37.786
2005	38.069
2006	40.603
2007	39.368
2008	40.644
2009	43.452
2010	44.594
2011	44.166
2012	44.633
2013	44.945
2014	42.54
2015	37.646
2016	40.673
2017	41.082
2018	41.662
2019	42.323
2020	43.007
2021	43.75
2022	44.379