*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19727
19730
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
19841
19852
198622
198744
198852
198931
199017
199185
199240
19938
19943
199515
19967
199716
199810
199913
200015
200113
20022
200343
200424
20059
20066
20076
20085
20093
20103
20112
20128
201314
201414
20156
201614
20175
20180
20190
Total566