Year	Number of
1990	91.81
1991	95
1992	98.99
1993	102.65
1994	108.29
1995	111.71
1996	114.83
1997	119.65
1998	127.57
1999	135.29
2000	140.69
2001	143.06
2002	146.36
2003	152.67
2004	157.52
2005	159.17
2006	157.64
2007	158.08
2008	163.14
2009	169.2
2010	176.65
2011	181.66
2012	187.56
2013	195.83
2014	203.95
2015	212.01
2016	220.65