Year	Percent
1991	22.442
1992	23.517
1993	24.199
1994	25.569
1995	26.477
1996	27.438
1997	28.943
1998	30.381
1999	31.7
2000	32.764
2001	33.805
2002	34.944
2003	35.295
2004	36.276
2005	37.843
2006	39.452
2007	41.239
2008	42.382
2009	43.563
2010	44.637
2011	46.088
2012	47.513
2013	48.995
2014	50.544
2015	52.354
2016	53.527
2017	54.306
2018	55.371
2019	56.301
2020	57.163
2021	57.986
2022	58.717