Guild Wars 2

So according to:
http://wiki.guildwars2.com/wiki/Rune_of_Sanctuary
(and in game matches)

The minor rune #2 gives: +5% Boon Duration
The major rune #2 gives: +10% Boon Duration
But the superior rune #2 gives: +20% Frozen Duration

I think it’d be much better if it gave Boon Duration instead of Frozen Duration.

So according to:
http://wiki.guildwars2.com/wiki/Rune_of_Sanctuary
(and in game matches)
The minor rune #2 gives: +5% Boon Duration
The major rune #2 gives: +10% Boon Duration
But the superior rune #2 gives: +20% frozen duration
Is this intended? It doesn’t seem like it should be changing as it increases, and was hoping to equip it, but wanted the boon duration bonus.