*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19853
19860
19870
19881
19890
19900
19917
19926
19937
19942
19955
19960
19973
19980
19991
20001
20010
20021
20031
20041
20053
20062
20079
20080
20090
20100
20110
20120
20130
20141
20150
20161
20174
20180
Total59