*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19721
19730
19740
19751
19760
19770
19781
19790
19800
19811
19820
19831
19840
19850
19866
19874
198812
19895
19905
19918
19924
19932
19944
19955
19960
19978
19982
19994
20001
20013
200210
20033
200414
20052
20061
20071
20088
20090
20104
20116
20120
20130
20140
20150
20164
20170
Total131