Year	Number of
1990	1241.51
1991	1227.24
1992	1213.31
1993	1192.47
1994	1177.17
1995	1167.66
1996	1194.42
1997	1225.64
1998	1262.35
1999	1298.91
2000	1334.36
2001	1346.1
2002	1358.74
2003	1385.96
2004	1414.55
2005	1444.17
2006	1476.98
2007	1509.48
2008	1542.21
2009	1577.09
2010	1615.24
2011	1631.31
2012	1650.88
2013	1671.97
2014	1693.29
2015	1714.3
2016	1733.51