The CEO, Michael Weise owns 7,342,728 shares, and the new directors owns about 500,000, so nearly 8 million shares held by 2 directors, Most by the CEO, and they both bought more shares this month at retail at $2.25 to add to their holdings, they are not float, and are not selling, and must file form 4 reports if they sell.
So take your 15 million minus 8 million is 7 million float. But I think there is one more huge stock holder I am forgetting, a French JV firm perhaps?