Year	Number of
1990	1020.37
1991	1055.98
1992	1094.52
1993	1134.46
1994	1173.99
1995	1212.09
1996	1234.37
1997	1253.67
1998	1271.79
1999	1291.71
2000	1316.33
2001	1317.15
2002	1324.62
2003	1335.11
2004	1344.89
2005	1351.65
2006	1364.54
2007	1372.2
2008	1377.98
2009	1385.85
2010	1399.46
2011	1407.93
2012	1423.17
2013	1442.43
2014	1461.75
2015	1478.42
2016	1478.37