*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19720
19730
19740
19752
19760
19770
19780
19791
19800
19811
19821
19831
19840
19850
19860
19870
19880
19890
19900
19910
19920
19930
19940
19951
19960
19970
19981
19991
20000
20012
20020
20030
20040
20050
20061
20070
20080
20090
20102
20115
20127
20133
20140
20150
20160
20170
Total30