Angie,
The info I am seeing on a support case from a year ago indicates you should be able to import skills with proficiency by using a colon between the skill and the proficiency and a comma or a space between skills.
For example, in the Skills column:
Skill1:5,Skill2:3,Skill3:2,Skill4:4
It worked in my org, hopefully will work for you.
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George Ganahl GCP (PureCloud) ICCE
Principal Technology Consultant
Genesys
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