*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197275
197314
19740
19750
19760
19770
19780
19790
19801
19810
19820
19830
198423
19850
198628
198720
198882
198955
199063
199195
199237
199353
19947
19956
19961
19978
19984
199920
200045
200149
200225
20032
20041
20052
20060
20071
20084
20090
20101
20111
20121
20131
20140
20151
20161
20170
20180
20190
Total727