*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
19873
19880
19890
19900
19910
19920
19930
19940
19950
19960
19972
19980
19990
20000
20010
20022
20030
20040
20050
20060
20070
20081
20090
201013
201115
20122
20131
20140
20152
20161
20170
Total42