*Excludes Observations that spanned multiple years

Pre 19700
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19871
198810
19890
19901
19910
19927
19931
19940
19950
19961
19972
19981
19990
20000
20010
20020
20030
20040
20051
20060
200715
200813
200943
201024
20118
20121
20131
20145
20150
20161
20170
Total137