crash.re

 let percentCovered = (x, y) => {
    let (x, y) = (min(x, y), max(x, y));
    let amountCovered = sites^ |> List.fold_left((sum, site) => {
      sum +. (min(site.right, y) -. max(site.left, x))
    }, 0.0);

    100.0 *. amountCovered /. (y -. x);
  };