*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
198510
19864
19872
198822
19891
199014
199127
19927
19930
19941
19950
19960
19970
19980
19992
200016
20012
20025
20030
20040
20059
20060
20070
20083
20093
20100
20112
20120
20130
20140
20153
20161
20170
20180
20190
Total134