2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
48.0
50.0
52.0
54.0
56.0
58.0
60.0
62.0
64.0
66.0
68.0
70.0
72.0
74.0
76.0
78.0
80.0
82.0%
Overall
Full-time
Part-time
