*Excludes Observations that spanned multiple years

Pre 19707
19700
19711
19720
19730
19740
19750
19760
19770
19780
19790
19800
19810
19820
19831
19840
19850
19860
19879
198830
19896
19904
199110
19923
199320
19947
199524
199624
199724
19980
199930
20003
20013
20023
20036
20044
20050
20060
20071
20083
20093
20101
20115
20120
20131
20141
20157
20162
20171
20182
20192
20205
20215
20222
20232
20246
Total268