*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19751
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
198814
19890
19904
19914
19925
19937
19942
199516
199613
199711
19986
19991
20003
20010
20020
20031
20041
20052
20062
20071
20087
20090
20100
20111
20120
20130
20142
20150
20160
20170
Total104