*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19891
19900
19910
19921
19931
19940
199517
199612
199724
19983
19997
200010
20010
20021
20030
200410
20051
20060
20070
20083
20091
20101
20110
20120
20130
20140
20151
20160
20170
Total94