*Excludes Observations that spanned multiple years

Pre 197010
19701
19711
19720
19730
19741
19750
19760
19770
19780
19790
19800
19810
19820
19830
19840
19850
19860
19870
19880
19890
19900
19912
19922
19937
19946
199510
19964
19979
19986
19996
200030
20018
20027
20030
20043
20051
200612
200711
20080
20096
20103
20110
20127
20134
20140
20150
20160
20170
Total157