Carrie had a homework assignment where she had to chart the amount of snowfall during a 4 month period over 2 consecutive years. In January of the first year, it snowed 3 inches, and in the second year, it snowed 5 inches. In February of the first year it snowed 1.5 inches, and in the second year, it snowed 4 inches. In March of the first year, it snowed 2.5 inches, and in the second year, it snowed 7 inches. In April of the first year it snowed 4 inches, and in the second year, it snowed 6 inches. In which month did the highest ratio of snowfall?