Year	Percent
1991	32.052
1992	29.432
1993	29.235
1994	30.386
1995	28.987
1996	29.098
1997	29.47
1998	35.793
1999	32.728
2000	32.95
2001	32.766
2002	32.208
2003	32.434
2004	32.329
2005	32.583
2006	33.24
2007	33.444
2008	33.67
2009	33.364
2010	32.072
2011	32.182
2012	30.851
2013	33.223
2014	32.225
2015	32.248
2016	32.717
2017	32.748
2018	32.583
2019	32.416
2020	32.251
2021	32.108
2022	31.968