*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19731
19740
19755
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19909
19911
19929
19930
19940
19954
19962
19975
19983
19997
20006
20015
20021
20032
20044
20053
20060
20073
20084
20090
20100
20112
20129
20130
20140
20150
20160
20170
Total85