perfect keyword density %

I have found the easy seo plugin to be inconsistent and use an add on for firefox, using both gives a better analysis. I do make sure that my keywords begin the title, description and is in the first and last paragraph. Italics, under line and bold is another. keyword with an internal and external anchor link is another. I have found that the easy seo plugin has taught me what keywords are needed to be modified and together with regular fresh and unique content and back links will hopefully achieve a good position with Google.

1 - 1.5 is optimal. I wouldnt worry too much about density. Take into more
consideration is the article readable. Keyword density still applies but not as
much these days. It more based around social activity.

I can add that the density you can chek with Seoquake