Do not write your content around a keyword density %, the magic number was between 4-7%. However now a days you will find writing quality content that is original will be better for a long term marketing strategy. Setting up proper inner site link structure will be more beneficial for you then trying to target a certain % of keywords used.
Really don't concentrate much on the density, add your content and try to include around 5 times the key word in it. If more will feel its as spam may be harm to the site. Concentrate on promotion like link building and content updation
Its totally useless to talk about keyword density. Who is expert in his field will write natural content and I am damn sure that this natural content looking to the visitors will 100% fulfill the keyword density cirteria