*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197217
19732
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
198411
19852
198614
198730
198866
198935
199056
199149
199227
199312
19948
19957
199611
19977
19985
199931
200037
200142
200213
20032
20042
20051
20060
20071
20081
20090
20103
20116
20120
20130
20141
20151
20166
20171
20180
Total508