Year	Number
1993	9.34049
1994	9.27705
1995	9.09961
1997	10.36892
1998	17.95752
1999	17.10307
2000	16.51625
2001	16.12259
2002	15.2131
2003	14.33783
2004	9.02021
2005	9.21652
2006	9.24242
2007	9.51771
2008	9.70387
2009	9.71288
2010	9.82451
2011	9.53555
2012	9.54331
2013	13.33478
2014	13.8611
2015	14.24678
2016	14.18929
2017	14.66121