def METHOD_NAME(self, data):
    total = {"numerator": 0, "denominator": 0}
    for d in data:
        if (
            (d["date"] == "2015-07-01")
            or (d["date"] == "2015-08-01")
            or (d["date"] == "2015-09-01")
        ):
            total["numerator"] += d["numerator"]
            total["denominator"] += d["denominator"]
    total["calc_value"] = (total["numerator"] / float(total["denominator"])) * 100
    return total