Year	Number
1984	34.82879
1986	56.02557
1987	54.84598
1988	41.03495
1989	31.82453
1990	41.8418
1999	41.8339
2011	34.017
2012	33.12716
2013	31.69309
2014	32.80488
2015	32.98337
2016	32.77201
2017	31.74918
2018	31.00561