Year	Percent
1992	4.15398
1993	5.65173
1994	5.17878
1995	6.93148
1996	5.79002
1997	18.09565
1998	20.6448
1999	22.66881
2000	26.53429
2001	24.23191
2002	24.93344
2003	25.75539
2004	29.0528
2005	25.82749
2006	24.11859
2007	23.79266
2008	23.30431
2009	24.93819
2010	24.06745
2011	22.73168
2012	17.94199
2013	16.34248
2014	13.70851
2016	14.03834