*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19849
19850
198644
198766
198891
198969
199071
199181
199270
199369
199461
199560
199669
199750
199862
199971
200050
200157
200233
200341
200423
200518
200620
20074
20085
20097
201052
201127
201237
20132
20143
20150
20160
20170
Total1322