*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19771
19780
19791
19800
19811
19820
19834
19840
19851
19860
198724
198885
19897
199012
199122
199247
199394
199417
199532
199612
19974
19984
199935
200075
200133
200235
20037
200412
200526
200615
200720
200846
200938
20105
20117
20120
20130
20142
20150
20166
201717
201816
201913
20201
20210
Total777