Interesting, I'm used to the US market. Back when I was a regular user (as opposed to sometimes-caving-and-buying-a-dispo quitter), salts were usually 25 and 50, with lower strengths provided by freebase nicotine juices. I think the last freebase juice I bought was a 3 or 6mg, but those were less common.

Disposables are usually 5% salts over here, afaik.