*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19841
19850
19860
19871
19885
19891
19904
19911
19922
19931
19947
19952
19961
19972
19981
19990
200039
20017
20023
200311
20047
200524
200637
200710
200821
200919
201031
201145
201225
201325
201410
20151
20161
20170
Total346