*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19854
19860
19876
19884
19890
19908
19910
19922
19931
19940
19950
19960
19972
19980
19990
20000
20010
20021
200313
20040
20050
20062
20074
20081
20090
20100
20110
20120
20131
20140
20150
20161
20170
20182
Total52