Year	Number of
1990	248.91
1991	255.54
1992	262.81
1993	271.61
1994	282.51
1995	295.38
1996	289.95
1997	282.69
1998	275.41
1999	267.31
2000	260.04
2001	261.08
2002	266.03
2003	268.85
2004	271.47
2005	274.12
2006	277.15
2007	279.18
2008	283.46
2009	291.31
2010	301.46
2011	310.31
2012	318.07
2013	326.09
2014	335.04
2015	350.52
2016	367.88