*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
19913
19920
19930
19944
19953
19969
19972
19983
19998
20000
20013
20021
20033
200433
20058
20063
200717
20083
200930
20100
20111
201210
20132
20140
20150
20162
20170
Total148