Year	Percent
1991	27.028
1992	22.621
1993	24.18
1994	22.54
1995	25.922
1996	25.74
1997	24.423
1998	31.489
1999	35.648
2000	35.693
2001	36.582
2002	33.961
2003	34.061
2004	32.17
2005	30.664
2006	29.131
2007	28.668
2008	29.044
2009	25.52
2010	26.646
2011	29.463
2012	27.906
2013	27.685
2014	27.896
2015	26.586
2016	26.243
2017	26.281
2018	26.203
2019	25.894
2020	25.841
2021	25.881
2022	25.876