Year	Number
1999	20.73828
2000	21.47244
2001	19.93609
2002	16.59365
2003	16.55108
2004	16.52866
2005	14.55211
2006	21.24291
2007	20.61961
2008	17.53497
2009	16.7993
2010	14.86942
2011	14.66192
2014	13.96923