Year	Number of
1990	217.2
1991	222.55
1992	229.41
1993	236.67
1994	244.17
1995	255.3
1996	267.26
1997	274.28
1998	275.21
1999	268.38
2000	255.51
2001	245.84
2002	240.18
2003	238
2004	237.43
2005	237.14
2006	234.05
2007	229.72
2008	228.69
2009	234.16
2010	241.46
2011	242.11
2012	241.85
2013	242.77
2014	242.3
2015	247.92
2016	254.37