*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19911
19920
19930
19940
19950
19960
199795
19980
19990
20001
20015
200292
20030
20049
20051
20060
20071
20080
20090
20100
20111
20120
20132
20141
20153
20161
20176
20189
Total228