[Client] (Possibly [Gameplay]) Inconsistent Mana Regen Per Level Rune Math

Foreword, this makes more sense if you examine the picture I linked, the following may be poorly phrased.

It is my understanding that mana regeneration runes are Primary as Seals and Secondary as Glyphs. Primary runes are superior in all statistics when compared to their Secondary counterparts. Greater Seal of Scaling Mana Regeneration is 0.065 mana per 5 seconds per level. 0.065 x 18 = 1.17 at level 18, which is consistent with the rune's description and is rounded up to 1.2 at level 18 in the Runes Statistics summary sidebar. Greater Glyph of Scaling Mana Regeneration is 0.06 mana per 5 seconds per level. 0.06 x 18 = 1.08 at level 18, which is NOT consistent with the rune's description, which states 1.2 at level 18; the Runes Statistics summary sidebar also reflects this number. Where is this extra 0.12 coming from? The description should be 1.08, the sidebar should be 1.1 if it rounds up properly. It is my hope that this is purely a cosmetic error.