*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19782
19790
19800
19810
19820
19831
19840
19852
19860
19871
19880
19891
19900
19911
19921
19932
19942
19957
19960
19971
19981
19991
20001
20010
20020
20030
20040
20052
20062
20072
20080
20091
20100
20110
20120
20132
20140
20150
20160
20170
Total33