Year	Percent
1991	5.5247
1992	3.71481
1993	4.67918
1994	2.81995
1995	2.66503
1996	2.68693
1997	3.45333
1998	6.65681
1999	6.2209
2000	5.42058
2001	7.13285
2002	8.30981
2003	8.86945
2004	3.28514
2005	2.86473
2011	3.42516
2012	12.07868
2013	13.00064
2014	21.24251
2015	23.80218
2016	27.63585