Year	Number of
1990	136.02
1991	140
1992	143.91
1993	148.75
1994	152.98
1995	159.35
1996	164.64
1997	172.83
1998	181.25
1999	190.05
2000	197.7
2001	204.6
2002	212.76
2003	221.11
2004	229.56
2005	239.59
2006	248.75
2007	258.35
2008	269.62
2009	280.47
2010	291.04
2011	301.24
2012	312.26
2013	323.81
2014	337.69
2015	351.46
2016	364.2