*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
19890
19900
19910
19920
19930
19940
19952
19960
19971
19980
19993
200031
200127
200270
20039
200457
200517
200674
20070
20084
20094
201013
20114
20126
201310
201410
201516
201672
201725
20184
Total459