top	bottom	era	ratio
745	1150	60s	0.65
750	1090	60s	0.69
748	1190	70s	0.63
762	1190	60s	0.64
770	1310	70s	0.59
770	1312	70s	0.59
775	1084	60s	0.71
775	1235	60s	0.63
776	1094	early 60s	0.71
778	1162	early 60s	0.67
789	1309	60s	0.60
797	1244	60s	0.64
800	1400	60s	0.57
810	1200	60s	0.68
818	1396	60s	0.59
820	1165	early 60s	0.70
824	1178	70s	0.70
824	1182	70s	0.70
825	1165	60s	0.71
826	1104	70s	0.75
826	1260	early 60s	0.66
827	1192	70s	0.69
830	1172	60s	0.71
840	1240	60s	0.68
840	1240	60s	0.68
840	1325	70s	0.63
842	1321	70s	0.64
844	1188	60s	0.71
845	1189	70s	0.71
850	1232	60s	0.69
856	1080	70s	0.79
857	1152	60s	0.74
861	1318	60s	0.65
865	1080	70s	0.80
868	1360	70s	0.64
872	1377	2013	0.63
876	1224	60s	0.72
876	1258	70s	0.70
878	1068	60s	0.82
878	1234	60s	0.71
878	1328	60s	0.66
886	1164	70s	0.76
890	1140	late 60s	0.78
894	1122	60s	0.80
898	1286	60s	0.70
900	1285	60s	0.70
902	1264	60s	0.71
904	1278	60s	0.71
910	1130	60s	0.81
912	1114	60s	0.82
937	1419	2013	0.66
938	1335	82-91	0.70
940	1451	2013	0.65
955	1433	2013	0.67
956	1402	70s	0.68
958	1380	2013	0.69
960	1480	80s	0.65
962	1437	80s	0.67
968	1372	hollow ink	0.71
975	1300	early 60s	0.75
978	1292	80s	0.76
997	1270	80s	0.79
1008	1490	2013	0.68
1020	1304	A & Cie	0.78
1020	1450	CO	0.70
1023	1389	1997	0.74
1030	1280	60s	0.80
1035	1480	70s	0.70
1036	1498	80s	0.69
1036	1498	92	0.69
1061	1308	post 1992	0.81
1085	1474	1997	0.74
1085	1484	post 1998	0.73
1086	1389	mid 70s	0.78
1086	1415	82-91	0.77
1086	1488	70s	0.73
1097	1497	laser	0.73
1122	1368	82-91	0.82
1128	1389	82-91	0.81
1190	1388	60s	0.86
1190	1477	70s	0.81
1200	1535	70s	0.78
1250	1600	JD 2004	0.78
Average	Average	Correlation	Ave Ratio
918.37	1295.82	0.72	0.71