*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19783
19791
19801
19810
19820
19830
19840
19851
19860
19870
19883
19892
199013
199142
199230
199318
19949
199511
19969
199717
199810
19996
20003
200111
20026
20030
20041
20050
20061
20072
20084
20090
20100
20110
201254
20130
20140
20150
20164
20170
Total262