*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19763
19772
19781
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19891
19900
19910
19921
19931
19942
19957
19963
19976
19989
19994
20000
20010
20020
20031
20041
20050
20060
20070
20080
20090
20100
20110
20120
20130
20140
20150
20160
20170
Total42