Year	Percent
1991	12.744
1992	13.323
1993	13.627
1994	14.548
1995	15.555
1996	16.048
1997	17.118
1998	18.118
1999	18.625
2000	19.725
2001	20.407
2002	20.974
2003	21.483
2004	22.16
2005	23.02
2006	24.2
2007	25.21
2008	25.724
2009	25.629
2010	25.897
2011	26.452
2012	27.524
2013	28.018
2014	27.662
2015	27.607
2016	28.543
2017	28.679
2018	29.154
2019	29.56
2020	30.065
2021	30.496
2022	30.947