Rune frequency

[Whitewings]

Is the rune foraging skrit designed to yield a roughly equal probability of any given type of rune coming up ona givin foraging attempt, or it is deliberately skewed? I'm wondering because out of a total of 12 runes (and four magic snowballs), I've only found 2 runes of protection.

[Artamos]

Luck of the draw I'm afraid..

Keep a snowball in your inventory and then you won't get any more..

[Whitewings]

I've been doing that since I first read about it. I don't need any more snowballs.