Year	Number of
1990	2445.75
1991	2335.44
1992	2419
1993	2401.76
1994	2403.52
1995	2508.76
1996	2435.31
1997	2410.55
1998	2383.12
1999	2399.29
2000	2498.24
2001	2539.86
2002	2580.87
2003	2559.7
2004	2525.95
2005	2536.85
2006	2481.5
2007	2437.03
2008	2445.25
2009	2432.72
2010	2483.02
2011	2427.34
2012	2438.18
2013	2436
2014	2412.49
2015	2413.06
2016	2440.87