*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19851
19861
198711
19882
19894
199031
199113
19927
199320
19947
19956
19962
19971
19981
19994
20006
200118
20025
20036
20042
20051
20061
200712
20080
20092
20102
201112
20124
201313
20146
20154
20163
20172
20185
20190
20200
20210
20220
Total215