*Excludes Observations that spanned multiple years

Pre 19703
19701
19710
19720
19730
19740
19750
19760
19770
19780
19791
19803
19810
19820
198315
19848
19852
198654
198715
198838
198944
199011
199151
199254
199393
199450
199549
199638
199730
199820
199921
20003
20015
200219
20033
200415
200582
20062
20071
20088
20094
20102
201114
20120
20131
20144
20154
20166
20173
20180
Total777