Year	Number of
1990	1689.97
1991	1636.22
1992	1578.19
1993	1517.93
1994	1461.72
1995	1412.64
1996	1361.44
1997	1317.3
1998	1278.87
1999	1244.34
2000	1212.58
2001	1204.45
2002	1196.85
2003	1192.96
2004	1189.32
2005	1185.94
2006	1209.96
2007	1235.06
2008	1261.4
2009	1289.73
2010	1320.86
2011	1325.1
2012	1332.1
2013	1338.16
2014	1346.7
2015	1358.47
2016	1377.03