*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19751
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19883
19890
19900
19911
19920
19930
19944
19955
19961
19970
19980
19990
20001
20011
20021
20030
20044
20050
20060
20070
20081
20090
201031
201128
20121
20130
201413
20150
20160
20170
Total96