It’s been an eon since I promised myself to get this Keyword Density Analyser up and running.
Take a look at the options available from only including certain tags in the mix and adding your own stopwords.
It does not look the prettiest in terms of columns, but it is a fine bit of programming. A fine bit of programming I cannot take credit for. For that you will have to look to Brotherhood of Lan.
Try it here >> KWDA