*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19882
19892
19900
19910
19920
19931
19940
19953
19961
19972
19984
19997
20002
20010
20022
20039
20043
20053
20060
20070
20082
20092
20101
20110
20120
20130
20140
20150
20160
20170
Total46