*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19862
19872
198813
19894
19907
199131
19921
19930
19943
19951
19965
19971
19980
19994
20002
200111
20023
20032
20040
20050
20060
20070
20081
20091
20104
20111
20120
20133
20140
20150
20161
20170
20180
Total105