*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19801
19810
19821
19838
19841
19851
19862
198714
198829
198910
199011
199110
199221
199313
199411
199512
19965
199714
199812
19997
200013
20016
20025
20035
20048
200516
20066
200721
20089
20095
20102
20110
20124
20130
20141
20150
20160
20170
Total284