The transaction volume increased tenfold from 5 million to 50 million Dollars per day over the last two years. I would love to know how much of that are useful

The transaction volume increased tenfold from 5 million to 50 million Dollars per day over the last two years. I would love to know how much of that are useful Dollars, i.e. people buying stuff and paying for services, as opposed to speculation, moving coins around for the sake of it or mining coins and selling them to pay the electricity bill.