Year	Number of
1990	1931.78
1991	1912.88
1992	1884.07
1993	1891.02
1994	1858.97
1995	1809.45
1996	1734.39
1997	1648.76
1998	1590.48
1999	1540.02
2000	1476.35
2001	1447.24
2002	1425.05
2003	1403.81
2004	1397.3
2005	1391.13
2006	1390.47
2007	1390.98
2008	1393.09
2009	1399.24
2010	1407.64
2011	1418.93
2012	1436.56
2013	1454.07
2014	1473.49
2015	1493.73
2016	1509.57