AUGUSTA, Maine — The number of girls competing in high school wrestling across the country has increased during each of the past 28 years. That national trend has been perhaps most noticeable over the past six winters, when the roster of schoolgirl wrestlers has grown from 8,235 in 2012 to 14,587 for the 2017-18 season, according to an annual survey compiled by the National Federation of State High School Associations. The recent girls wrestling boom has not been nearly as robust in Maine, but supporters of the sport hope the first girls-only individual state championship tournament sanctioned by the Maine Principals’ Association planned for February 2019 will spur increased interest. “The hope is more girls will participate,” said MPA assistant executive director Mike Bisson. The proposal has passed through the MPA wrestling committee as well as its Interscholastic Management Committee and needs only an affirmative final vote from the organization’s general membership at its fall conference in November to take place for the first time Feb.