Year	Number of
1990	1197.09
1991	1188.88
1992	1201.26
1993	1221.49
1994	1257.37
1995	1277.21
1996	1306.85
1997	1320.23
1998	1328.27
1999	1308.66
2000	1325.63
2001	1339.74
2002	1353.02
2003	1386.37
2004	1416.95
2005	1479.6
2006	1510.9
2007	1526.53
2008	1519.63
2009	1522.41
2010	1528.8
2011	1528.14
2012	1540.1
2013	1552.06
2014	1541.48
2015	1547.75
2016	1556.32