Year	Number of
1990	289.32
1991	300.25
1992	311.15
1993	323.72
1994	334.95
1995	346.31
1996	351.01
1997	355.5
1998	356.59
1999	362.12
2000	367.43
2001	371.57
2002	375.6
2003	379.01
2004	382.15
2005	384.65
2006	386.76
2007	389.78
2008	394.09
2009	399.58
2010	405.25
2011	413.33
2012	422.62
2013	431.09
2014	441.52
2015	459.15
2016	478.03