The estimated number of foreigners arriving in Japan in January was down 61.7 percent from a year earlier to 17,800 people, due to strict border controls introduced to prevent the spread of the Omicron variant of the coronavirus, government data showed Wednesday. The year-on-year number fell for the fourth month in a row. Since Nov. 30, Japan has banned entry by nonresident foreigners in principle, with authorities still struggling to stem the spread of the highly transmissible variant. In January, the largest number came from India at 2,100 people, followed by the United States at 1,800, Chin…