*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19741
19750
19761
19770
19780
19792
19801
19810
19821
19830
19841
19852
19860
19870
19885
19890
19901
199127
199223
199326
19946
199537
19960
19976
19987
19990
20006
20017
20023
20030
20048
20051
20063
20070
20087
20095
201012
201120
20126
20132
20144
201510
20167
201711
201812
201942
20201
20210
20220
Total315