Reviewing the financial statements of KRJ Enterprises $($all figures in $ millions$),$ you find the following items: total debt of $$540,$ total liabilities of $$836,$ total cash and marketable securities of $$99,$ operating earnings of $$188,$ and depreciation and amortization expenses of $$57.$ Calculate the net debt to EBITDA ratio. Present your answer rounded to two decimal places $($e$.$g$.,2\mathrm{.}34).$