*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19752
19760
19770
19782
19790
19801
19810
19820
19832
19841
19851
19862
19874
198813
198912
19900
199114
199213
199331
19945
19958
19961
19971
19983
199917
200023
200110
200211
20033
20045
20050
20060
20070
200820
200912
20101
20110
20121
20130
20141
20150
20161
20173
20182
20195
20204
20211
20220
Total236