*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19772
19780
19791
19800
19810
19822
19830
19840
19854
198620
198715
198882
198927
199016
199150
199217
199330
19942
199558
199614
19979
199818
199951
200067
200130
20026
20033
20044
20059
200610
200728
20084
200911
20100
20111
20120
20130
20144
20153
201614
20172
20186
20194
20200
20210
20220
Total625