Year	Percent
1991	24.637
1992	23.259
1993	25.622
1994	25.526
1995	25.726
1996	26.229
1997	26.598
1998	27.02
1999	27.505
2000	27.743
2001	27.779
2002	28.321
2003	28.461
2004	28.646
2005	29.481
2006	28.467
2007	29.423
2008	29.778
2009	29.818
2010	30.521
2011	31.279
2012	31.767
2013	32.236
2014	32.387
2015	32.891
2016	33.79
2017	33.506
2018	33.892
2019	34.379
2020	34.764
2021	35.074
2022	35.429