Year	Number of
1990	1241.92
1991	1258.37
1992	1277.21
1993	1296.94
1994	1309.97
1995	1319.23
1996	1315.45
1997	1326.47
1998	1323.63
1999	1339.01
2000	1348.29
2001	1358.05
2002	1386.88
2003	1408.88
2004	1434.67
2005	1464.41
2006	1487.02
2007	1510.9
2008	1536.17
2009	1561
2010	1587.21
2011	1608.5
2012	1633.72
2013	1660.22
2014	1688.49
2015	1717.12
2016	1744.46