Year	Number of
1990	162.57
1991	172.47
1992	182.92
1993	194.95
1994	208.71
1995	223.86
1996	239.49
1997	256.79
1998	279.68
1999	302.48
2000	317.02
2001	332.27
2002	344.41
2003	356.83
2004	366.9
2005	376.3
2006	385.46
2007	393.73
2008	402.09
2009	420.48
2010	433.37
2011	447.79
2012	460.34
2013	464.46
2014	465.84
2015	470.79
2016	478.99