"Not less than" 또는 "no less than"

"Not less than X" is an alternative way of saying "X or higher/more", or "at least X". 

It usually forms part of some formal condition:

"Applicants for migration must ensure they have not less than $20,000 in immediately accessible private funds."

But

"His diet is going really well. He has lost no less than 15 kilos already."

That is not saying "at least 15 kilos"; it's more or less exactly 15 kilos, but it's emphasizing the amount he's actually lost when a lower amount might have been expected.

"He was expecting to have lost 20 kilos by now, but he's managed to shed no more than 5 kilos."