Year	Number of
1990	102.96
1991	114.14
1992	126.47
1993	140.3
1994	155.61
1995	172.66
1996	181.73
1997	191.36
1998	201.57
1999	212.24
2000	223.46
2001	227.1
2002	230.7
2003	234.43
2004	238.27
2005	242.41
2006	243.72
2007	245.07
2008	246.91
2009	248.78
2010	250.79
2011	257.68
2012	264.88
2013	272.3
2014	280.07
2015	288.24
2016	297.05