Year	Number of
1990	201.39
1991	206.98
1992	215.44
1993	224.12
1994	233.53
1995	241.77
1996	246.51
1997	252.18
1998	261.69
1999	272.49
2000	277.38
2001	276.47
2002	276.54
2003	279.38
2004	280.53
2005	283.07
2006	281.26
2007	277.13
2008	271.29
2009	267.85
2010	268.27
2011	270.12
2012	271.92
2013	273.9
2014	276.5
2015	279.06
2016	282