Year	Number of
1990	226.43
1991	237.11
1992	248.91
1993	262.27
1994	275.84
1995	289.08
1996	300.56
1997	311.36
1998	321.94
1999	333.94
2000	346.54
2001	358.89
2002	370.81
2003	384.12
2004	398.8
2005	414.24
2006	430
2007	444.97
2008	460.85
2009	476.54
2010	492.73
2011	511.57
2012	532.67
2013	555.09
2014	577.57
2015	600.09
2016	629.08