*Excludes Observations that spanned multiple years

Pre 19700
19700
19710
197226
197323
19740
19750
19760
19770
19780
19790
19800
19810
19820
19830
19844
19857
198612
19877
198831
198918
199068
1991124
1992129
199323
19941
19950
19961
19970
19980
199920
200034
20013
20020
20030
20041
20055
20063
20071
20088
20090
201045
201117
20122
20136
20140
20151
20164
20174
201844
20190
Total672