Year	Number of
1990	141.66
1991	150.66
1992	160.87
1993	167.8
1994	178.95
1995	189.93
1996	194.8
1997	208.26
1998	213.42
1999	224.32
2000	234.07
2001	248.8
2002	262.87
2003	276.66
2004	291.15
2005	300.74
2006	309.75
2007	316.31
2008	327.9
2009	340.68
2010	354.04
2011	365.59
2012	381.15
2013	394.26
2014	406.96
2015	419.61
2016	434.33