*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19863
19871
19884
19894
199025
19914
19921
19930
19940
19953
19960
19978
19980
199918
200020
200111
20023
20032
20044
20050
20060
20071
20082
20090
20100
20110
20120
20132
20140
20150
20160
20170
20180
Total118