6 points
The only other pair sharing the same number are Russia and Kazakhstan with 7
4 points
*
All of the USSR was +7 IIRC. Most changed it after independence, notice how the Baltics, Belarus and whatnot have previously unassigned three-character numbers instead of two like most of Europe (except microstates). They only got their numbers in the 90s, and no shorter ones were available. +37 just became available since east Germany didn’t exist anymore.
Same with the former Yugoslavian countries, all of YU used +38, when they split up they had to split up +38 too.
