*Excludes Observations that spanned multiple years

Pre 197015
19700
19710
19720
19730
19740
19751
19760
19771
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19910
19920
19930
19940
19950
19960
19974
19980
19992
20000
20010
20020
20031
20041
20052
20060
20071
20080
20090
20101
20110
20120
20130
20140
20151
20160
20170
Total30