Year	Number of
1990	349.73
1991	359.74
1992	370.56
1993	380.19
1994	385.17
1995	393.3
1996	406.43
1997	416.38
1998	422.77
1999	433.24
2000	445.4
2001	463.25
2002	471.32
2003	485.9
2004	497.01
2005	507.14
2006	514.74
2007	517.56
2008	526.04
2009	535.97
2010	541.6
2011	555.23
2012	572.33
2013	587.07
2014	596.91
2015	609.48
2016	621.75