*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19852
19860
19870
19881
19890
19900
19917
19925
19937
19942
19955
19960
19973
19980
19991
20001
20010
20020
20031
20040
20053
20061
20078
20080
20090
20100
20110
20120
20130
20141
20150
20161
20170
Total49