Year	Number of
1990	1472.56
1991	1490.9
1992	1518.18
1993	1528.25
1994	1521.88
1995	1534.9
1996	1534.43
1997	1523.47
1998	1505.68
1999	1505.89
2000	1480.44
2001	1481.83
2002	1491.35
2003	1459.56
2004	1447.17
2005	1438.26
2006	1433.43
2007	1424.78
2008	1410.87
2009	1418.02
2010	1404.01
2011	1379.91
2012	1354.68
2013	1335.01
2014	1317.48
2015	1317.08
2016	1318.57