*Excludes Observations that spanned multiple years

Pre 19701
19700
19710
19721
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19842
19850
19864
19878
198842
19893
199034
199177
199264
199341
19941
199513
19960
199721
19980
199934
200019
200116
20024
20032
20040
20051
20060
20070
20081
20091
201027
201153
20122
20136
20140
20150
20161
20172
20180
Total482