*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19791
19800
19810
19824
19831
19840
19850
19863
19872
19882
19890
19900
19910
19920
19936
19944
19954
19961
19970
19980
19990
20001
20011
20023
20036
20041
20050
20062
20072
20081
20090
20100
20112
20120
20130
20140
20150
20160
20170
Total47