Year	Number of
1990	104.33
1991	114.33
1992	126.55
1993	141.95
1994	159.92
1995	178.92
1996	196.34
1997	210.6
1998	221.28
1999	227.95
2000	231.26
2001	234.42
2002	238.1
2003	242.99
2004	243.71
2005	251.32
2006	253.82
2007	255.35
2008	257.2
2009	258.92
2010	261.06
2011	262.17
2012	267.06
2013	277.85
2014	288.48
2015	299.57
2016	309.97