*Excludes Observations that spanned multiple years

Pre 19703
19700
19711
19720
19730
19740
19751
19760
19770
19781
19790
19800
19810
19821
19834
19840
19850
198637
19871
19881
198912
199015
19916
199210
199311
19943
19958
19961
199710
199816
199917
20001
200120
20025
20033
200452
20059
20062
20071
200810
20091
201011
20119
20120
20133
20142
201512
201612
201716
20180
Total328