Year	Number of
1990	280.95
1991	289.68
1992	281.13
1993	273.87
1994	268.3
1995	268.72
1996	270.19
1997	276.38
1998	276.12
1999	279.58
2000	269.78
2001	272.94
2002	270.3
2003	272.27
2004	271.61
2005	268.16
2006	265.96
2007	270.14
2008	260.21
2009	258.95
2010	262.12
2011	262.58
2012	262.76
2013	261.63
2014	256
2015	256.2
2016	256.33