def parse_claspre_value(raw_value):
    """Convert values from claspre to floats."""

    special = {
        "No": -1.0,
        "Yes": 1.0,
        "NA": 0.0,
        }

    value = special.get(raw_value)

    if value is None:
        return float(raw_value)
    else:
        return value