Year	Number
1996	16.73595
1997	16.30569
1998	322.15242
1999	16.25708
2000	16.1907
2001	16.72873
2002	16.37146
2003	16.32636
2004	16.26606
2005	16.05611
2007	15.10324
2008	14.5116
2009	14.04568
2010	13.7117
2011	13.13193
2012	12.68329
2013	12.03167
2014	11.67083
2015	11.17201
2017	10.13452