*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19860
19870
19880
19891
19904
199117
199210
199314
19947
19956
19961
19978
19984
19991
20001
200115
20024
20032
20040
20052
20060
20071
20084
20090
20100
20111
20120
20130
20140
20150
20161
20170
Total105