*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19881
19893
19902
19910
19921
19930
19940
199512
19961
19971
19982
19990
20008
20012
20020
20030
20041
20050
20062
20072
20082
20091
201018
20116
20120
20130
20140
20150
20160
20170
Total66