*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
19874
19880
19891
19900
19910
19920
19936
19940
19951
19961
19970
19981
19992
20000
20011
20020
20031
200431
20051
20063
20070
20081
20098
20100
20111
20123
20132
20141
20152
20165
20173
20181
20190
Total80