Year	Number of
1990	316.3
1991	319.21
1992	324.06
1993	333.02
1994	341.96
1995	354.16
1996	354.48
1997	359.09
1998	363.88
1999	366.91
2000	372.18
2001	376.01
2002	379.13
2003	382.3
2004	385.07
2005	384.42
2006	382.28
2007	385.25
2008	389.08
2009	397.13
2010	403.79
2011	409.31
2012	412.69
2013	418.13
2014	426.08
2015	434.31
2016	444.79