Table:
Fiscal Year	Variance in

(In millions, except for percentages)	2018	2017	Dollars	Percent

Net revenues	$2,554	$2,355	$199	8%

Percentage of total net revenues	53%	59%

Operating income	$473	$187	$286	153%

Operating margin	19%	8%

Answer the following question using the following table and its related text, respond with any necessary explanation, then provide the JSON object {"answer": ["ANSWER"], "scale": "SCALE"} as the final output (use an empty string for scale if irrelevant).

Context:
Segment operating results
Enterprise Security segment
Revenue increased $199 million primarily due to increases of $331 million in revenue from sales of our network and web security solutions and $36 million from sales of endpoint and information protection solutions, partially offset by a $184 million decrease in revenue as a result of the divestiture of our WSS and PKI solutions. Revenue during fiscal 2018 was also unfavorably affected by a shift in the mix of sales towards subscription and cloud-delivered solutions subject to ratable revenue recognition, which resulted in less in-period recognized revenue and more revenue deferred to the balance sheet as compared to fiscal 2017. Operating income increased $286 million primarily due to higher revenue discussed above, a $51 million decrease in sales and marketing expenses and a $38 million decrease in cost of revenues.

Question: What is the average Operating income for fiscal 2018 and 2017?

(473+187)/2, therefore {"answer": "330", "scale": "million"}