*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19852
19860
19870
19880
19890
19901
19911
19921
19938
19944
19950
19963
19973
19984
19991
20001
20010
20020
20030
20040
20051
20061
20072
20081
20092
20100
20111
20120
20130
20140
20150
20160
20170
Total38