Year	Number of
1990	1489.65
1991	1471.43
1992	1454.51
1993	1439.15
1994	1422.97
1995	1409.32
1996	1409.3
1997	1409.16
1998	1409.18
1999	1406.04
2000	1406.27
2001	1426.82
2002	1448.09
2003	1470.41
2004	1491.31
2005	1514.13
2006	1545.76
2007	1576.65
2008	1608.05
2009	1637.96
2010	1674.04
2011	1698.48
2012	1718.13
2013	1739.18
2014	1759.93
2015	1782.16
2016	1806.37