Year	Number
1996	15.6
1997	14.84
1998	17.24
1999	15.93
2000	13.35
2001	17.91
2002	12.65
2003	15.83
2004	25.27
2005	22.23
2006	26.82
2007	27.93
2008	30.99
2009	29.67
2010	34.25
2011	48.65
2012	55.51
2013	57.56
2014	62.16
2015	91.14
2016	96.88
2017	132.44
2018	99.85
2019	163.71
2020	153.54