*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19782
19790
19800
19812
19820
19831
19840
19850
19860
19871
19880
19890
19903
19910
19920
19930
199415
19954
19964
19970
19989
19994
20000
20012
20020
20031
20044
20052
20060
20074
20085
20094
20106
20110
20120
20130
20140
20150
20160
20170
20180
Total73