DUBAI: Dubai Duty Free has announced a 10% increase in sales for the first half of the year with turnover reaching Dhs3.671 billion (US$1 billion) and placing the operation well on track to reach Dhs7.400 billion (US$2 billion) by year-end. Liquor, Perfumes and Tobacco retained the top three category positions with Liquor showing a 7% increase year to date (YTD) …