Compute return on net operating assets (RNOA) Round answers to two decimal places (percentage ex: 0.12345 = 12.35%)

RNOA= Net operating profit after taxes/ Average of Net operating assets

net operating assets= operating assets - operating liabilites

What is RNOA? please show calulation

$ millions May 31, 2015 May 31, 2014 Operating assets $62,090 $57,002 Nonoperating assets 54,368 38,819 Total assets 116,458 95,821 Operating liabilities Nonoperating liabilities 20,180 19,055 41,958 24,097 Total liabilities 62,138 43,152 Total Oracle stockholders' equity 54,320 52,669 Total revenues 38,559 Operating income before tax Nonoperating expense before tax 13,993 1,037 Tax expense 3,498 Net income 9,458