*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19751
19760
19770
19780
19790
19801
19810
19820
19830
19840
19850
19860
19878
19881
19890
199015
199144
199237
199348
199425
199530
199650
199751
199841
199918
200012
200114
20025
20032
20046
20053
20066
200715
200828
200915
201013
201112
201216
201315
20148
201510
20167
201711
20187
20194
20200
20210
20220
Total579