*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19833
19840
19850
19861
19870
19881
19890
19900
19911
19921
19930
19941
19950
19960
19972
19980
19990
20000
20014
20020
20031
20040
20050
20063
20071
200810
20093
201060
201149
20124
20135
20144
20159
20169
20172
20180
Total174