*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19921
19931
19946
19954
199630
19976
19982
19993
200013
20013
200211
2003116
200490
2005141
200640
200784
2008332
20094121
201085
2011122
2012219
2013239
2014278
2015314
2016261
2017161
201864
20194
20200
20210
Total6751