*Excludes Observations that spanned multiple years

Pre 19701
19701
19710
19720
19730
19740
19750
19760
19770
19780
19790
19803
19810
19820
198314
19848
19852
198654
198715
198838
198944
19909
199151
199254
199389
199449
199548
199638
199729
199818
199920
20003
20013
200219
20033
200415
200581
20062
20071
20088
20093
20102
20116
20120
20131
20143
20158
20162
20171
Total746