Simplify the following text for a Grade 8 native English-speaking person.
Original: Although Ukraine was one of the three founding countries and ratified the Creation Agreement in December 1991 , Ukraine did not choose to ratify the CIS Charter and is not a member of the CIS .
Simplified: Before joining the CIS , on 21st December 1991 , leaders of these 11 countries had met in Kazakhstan to accept the original CIS agreement of 8th December 1991 . In December 1993 , Georgia also joined the CIS .