The value found on P.22_ Financial Performance _ CRS Report 2016
Average Exchange Rate: 1 USD= 1,160.5 KRW (https://www.statista.com/statistics/647920/krw-usd-annual-exchange-rate/).
1 USD = 1161.224877 KRW (2016)
(Calculation: 6,697.6*10^9/1161.224877 = 5,767,702,821.95737)
pg. 22
"Amorepacific Group (Unit: KRW bn)
Sales 2016
6,697.6"
I used the value given on page no. 22 of Amorepacific 2016 Sustainability Report and the avg. conversion rate (1161.224) as per the methodology of the question https://www.ofx.com/en-gb/forex-news/historical-exchange-rates/yearly-average-rates/