*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19882
19891
199015
199119
19926
19938
199412
199515
199611
199718
19983
19995
20007
20013
20029
200358
200435
200549
200643
200739
200832
200945
201041
201151
201296
201349
201440
201546
201642
201730
20180
Total830