Year	Number of
1990	200.87
1991	206.14
1992	208.93
1993	208.53
1994	210.99
1995	217.28
1996	223.8
1997	233.79
1998	245.52
1999	254.61
2000	263.5
2001	267.68
2002	276.83
2003	284.8
2004	289.72
2005	293.69
2006	295.05
2007	294.29
2008	297.48
2009	299.96
2010	300.28
2011	298.04
2012	298.24
2013	300.54
2014	304.41
2015	309.18
2016	313.02