*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19802
19812
19821
19833
19842
19851
19862
19872
19883
19892
19900
19911
19920
19930
19940
19950
19963
19974
19980
19993
20001
20011
20023
20030
20041
20050
20064
20073
20080
20090
20100
20111
20122
20131
20140
20150
20160
20170
20180
Total48