*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19851
19863
19874
198822
19892
19905
19915
19923
19939
19946
19954
19962
19975
19981
19991
20001
20010
20020
20033
20040
20051
20061
20070
20083
20093
20101
20110
20120
20130
20140
20150
20161
20170
Total88