Find average google pagerank for particular keywords

I need to develop web-based application that can compute or analyze the google average page rank of a keyword. It is the top 10 sites of that keyword in google. It is telling the script to add the pr of each 10 sites and divide it to 10. Let say, I will input 500 keywords in a web-form then click Get Average Page Rank. It will give result of 500 keywords with average PR beside each one of it. Option to sort PR from higher to lower, option to download as CSV. Option to use proxy server so not to get banned by google for many inquiry in one time. The interface is like the text box to input keyw开发者_如何学运维ords .output below but in 2 columns. 1 column for keyword and 1 column for average pr.

is there any google api available for this purpose ?

Thank you!

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There is no Google API for that and the very idea that there is a global average rank for a given keyword is flawed. A keyword's influence depends on the page's niche and the user's search request.