Year	Number
1996	24.456521987915
1998	24.456521987915
2000	26.0869560241699
2002	35.1351356506348
2003	21.6216220855713
2004	25.3731346130371
2005	15.6862745285034
2006	19.6078433990479
2007	18.9320392608643
2008	17.9611644744873
2009	15.3110046386719
2010	18.1818180084229
2011	17.5355453491211
2012	14.2180099487305
2013	15.1658763885498
2014	17.3076915740967
2015	15.7142858505249
2016	19.0476188659668
2017	11.9047622680664
2018	11.4285717010498
2019	13.8095235824585
2020	10.9523811340332
2021	17.1428565979004
2022	17.4528293609619