*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
19945
19956
19960
19978
19982
19994
20002
20013
200211
200320
200425
200515
200621
200712
200816
20097
201019
201126
201214
201324
201415
201523
201634
201724
20181
Total388