Enzyme problem, finding percentages

I aced biochem and I'm dying to see this answer because I haven't the faintest clue.

Some information that I suppose could get your thinking in the right path. In terms of percentage, I have never answered something like that

The imidazole sidechain of histidine has a pKa of approximately 6.0, and, overall, the amino acid has a pKa of 6.5. This means that, at physiologically relevant pH values, relatively small shifts in pH will change its average charge. Below a pH of 6, the imidazole ring is mostly protonated as described by the Henderson–Hasselbalch equation. When protonated, the imidazole ring bears two NH bonds and has a positive charge. The positive charge is equally distributed between both nitrogens and can be represented with two equally important resonance structures.

Heres what i did, but im not sure if its right...
I used the henderson hasslebalch equation, pH=pKa +log [imidizoleum]/[imidizole].

6.0=6.1 +log [imidizoleum]/[imidizole]
-0.1=log [imidizoleum]/[imidizole]
10^(-0.1)= [imidizoleum]/[imidizole]
[imidizoleum]/[imidizole]=0.794
[imidizoleum]/[imidizole]=0.794/1.794=0.44=44% imidizoleum
1/1.794=0.56=56% Imidazole

If anyone figures it out or knows if im right or now, lemme know cuz its due tomorrow =/