BOSTON — Not many people are taking advantage of the dozens of emergency shelters set up around Massachusetts for people left without power during the blizzard.A spokesman for the state Emergency Management Agency says fewer than 200 people have reported to shelters with a combined capacity of more than 7,500.The shelter at Plymouth North High School has the most people, about 25.In the adjacent town of Carver, 19 people are hunkering down at the high school.