*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19732
19740
19750
19760
19770
19781
19790
19800
19810
19820
19836
19841
19853
19863
198747
19883
198914
19902
19910
19921
19930
19943
199530
19960
19979
19982
19992
200010
20013
20020
20031
20044
20054
20065
200735
200814
200914
201016
201110
20123
20130
20142
20152
20165
20170
20180
Total257