title: Counting percent of rows with category out of total number of rows using Dynamic Linq
body: <p>How to achieve <a href="https://stackoverflow.com/questions/5981476/using-result-of-aggregate-from-top-level-group-inside-lower-level-group/5984203#5984203">this</a> using <a href="https://stackoverflow.com/questions/389094/how-to-create-a-dynamic-linq-join-extension-method/412868#412868">Dynamic Linq Join</a> and <a href="https://stackoverflow.com/questions/2983134/to-call-selectmany-dynamically-in-the-way-of-system-linq-dynamic#3302080">Dynamic Linq SelectMany</a></p>