How to build a query

Hello everyone!

In my table I have a column phone_numbers (varchar 30) that the
telephone numbers are stored in the following way (13 signs with spaces):

032 321 24 25
032 341 24 85
032 345 24 87

But in the same column there is also few hundred of mobile numbers that
i want to copy to another table. They were written in the following way
(11 signs with spaces):

606 605 504
506 504 548
879 504 152

Now I have a question: how to built a query that will give me only the
rows that are shorter than 13 signs (and maybe longer than 13 to check
if there is no mistakes)?

Regards,
Krzysztof Walkiewicz