*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19822
19831
19842
19850
19862
19872
19887
19890
199011
19919
199217
199330
199411
19954
19968
199724
19989
19996
20004
20017
200218
200314
20046
20051
20061
20076
20088
20091
20100
201110
20123
20132
20145
201515
201616
20173
20181
Total267