Year	Number of
1990	155.94
1991	159.91
1992	164.82
1993	174.29
1994	184.76
1995	192.16
1996	195.54
1997	198.92
1998	213.3
1999	214.45
2000	217.29
2001	223.62
2002	230.55
2003	242.53
2004	254.11
2005	263.91
2006	274.2
2007	282.39
2008	292.91
2009	303.19
2010	313.29
2011	321.35
2012	330.61
2013	341.27
2014	352.09
2015	363.82
2016	375.15