Year	Number of
1990	69.24
1991	72.96
1992	78.09
1993	83.78
1994	91.3
1995	98.55
1996	105.46
1997	113.39
1998	121.27
1999	126.13
2000	132.63
2001	139.27
2002	145.06
2003	153.15
2004	161.97
2005	169.24
2006	176.24
2007	182.57
2008	190.07
2009	199.41
2010	208.51
2011	216.04
2012	226.91
2013	236.78
2014	246.63
2015	256.38
2016	267.25