*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19861
19870
19880
19892
19905
19912
19922
19936
19942
19950
19965
19974
19981
19990
20001
20010
20023
20034
20043
20054
20063
20073
20086
20092
20105
20114
20128
20139
20145
20159
201611
20179
20180
Total119