*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19791
19800
19810
19821
19830
19840
19851
19862
19874
19880
19890
19900
19913
19922
19933
19940
199510
19969
19970
19980
19991
20001
20011
20020
20030
20040
20050
20060
20070
20081
20090
20100
20110
20120
20131
20140
20150
20160
20170
20180
20190
20200
Total42