*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19821
19830
19840
19852
19860
19870
19882
19890
19900
19910
19922
19930
19942
19950
19961
19970
19982
19991
200012
20010
20020
20031
20040
20050
20060
20070
20081
20090
20102
20113
20120
20130
20143
20150
20161
20170
Total36