Year	Number
1999	8.33565
2001	5.87452
2002	5.57909
2003	5.95642
2005	7.20507
2006	7.64644
2007	7.78088
2008	7.71405
2009	7.75696
2010	7.28683
2011	7.74777
2013	8.86643
2014	7.9582
2016	8.03991