O/Variants per time

Number of inscriptions containing variants of O per time span:

-750+	–	–	–	–	–	–	–	–
-650+	2	–	1	–	–	–	–	–
-550+	7	–	2	–	–	–	–	–
-450+	14	1	4	1	–	–	–	–
-350+	8	1	–	1	–	1	–	1
-250+	3	6	1	–	–	2	–	–
-150+	4	34	27	4	1	6	1	7
-50+	1	4	10	–	1	2	–	2
50+	–	1	1	–	–	–	–	–
150+	1	–	–	–	–	–	–	–