*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19850
19860
19870
19889
19890
19900
199121
19922
19938
19949
19953
19960
19970
19982
19990
20000
20012
20020
20030
20041
20052
20063
20072
20088
20091
20107
20111
20121
20130
20142
20151
20162
20172
20180
20190
Total90