*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19761
19770
19780
19790
19800
19810
19820
19830
19840
19850
19862
19870
19886
19894
19900
19910
19920
19936
19944
19953
19969
199715
19984
19994
20000
20010
20020
20031
20040
20050
20060
20070
20081
20090
201015
20112
20121
20131
20140
20150
20160
20170
Total79