Year	Number of
1990	108.96
1991	115.11
1992	121.51
1993	129.13
1994	137.34
1995	146.56
1996	152.56
1997	159.19
1998	166.64
1999	174.91
2000	183.81
2001	195.4
2002	206.17
2003	217.26
2004	228.02
2005	238.2
2006	248.45
2007	259.8
2008	273.42
2009	287.62
2010	302.13
2011	316.04
2012	330.48
2013	345.3
2014	361.16
2015	378.66
2016	400