*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19781
19790
19801
19811
19820
19831
19840
19850
19862
19871
198820
19894
199011
199117
19925
199316
199422
199510
199613
199719
19983
19991
20002
20013
20022
200317
200419
200536
200632
200724
200826
200929
201022
201137
201243
201344
201449
201545
201647
201753
20180
Total678