Sorry if something like this has been asked already. I did some forum hunting with no success.

I'm in a chest deep game and started the game with the skill suite of 10 skills.

+5+5
+4+4
+3+3
+2+2
+1+1

As I understand the rules of advancing skills it looks to me like I'll need something close to 17 significant/major milestones to raise one of my existing +4s to the +5 level. Am I missing something about the way the columns work? Thanks.

*Edited for spelling errors.