Year	Percent
1991	41.142
1992	40.573
1993	39.959
1994	39.883
1995	39.272
1996	38.338
1997	38.604
1998	37.078
1999	37.033
2000	37.255
2001	42.239
2002	39.095
2003	34.42
2004	34.441
2005	35.954
2006	35.64
2007	35.538
2008	31.333
2009	30.753
2010	30.567
2011	30.398
2012	27.282
2013	29.195
2014	31.377
2015	28.311
2016	27.855
2017	26.903
2018	26.202
2019	25.893
2020	25.569
2021	25.234
2022	24.836