Year	Number
1999	14.78678
2000	14.69451
2001	14.96983
2002	14.73684
2004	14.77462
2005	14.66565
2006	14.75651
2007	14.37072
2008	13.94827
2009	12.80372
2010	13.194
2011	12.72449
2013	13.98376
2014	11.53663
2015	12.14586
2016	14.41773
2017	12.11191