*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19848
19850
19860
19874
19881
19890
19900
19914
19922
19931
19940
19950
19960
19971
19980
19990
20003
20010
20020
20032
20040
20050
20062
20071
20081
20090
20101
20111
20122
20132
20140
20151
20162
20170
20181
Total40