def pct_change_from_x_to_y(number1, number2, *, precision="2"):  # pragma: no cover
    """
    Calculate percent increase/decrease from number1 to number2.

    Arguments:
        number1    (int): start value (from)
        number2    (int): end value (to)

    Keyword arguments (opt):
        precision  (int): number of digits after the decimal point
                          default is 2

    Returns:
        (str):  number

    Example:
    >>> pct_change_from_x_to_y(100, 110)  # what is the pct increase from 100 to 110?
    '10.00%'
    >>> pct_change_from_x_to_y(100, 90)   # what is the pct from 100 to 90?
    '-10.00%'
    >>> pct_change_from_x_to_y(25, 50, precision=0)
    '100%'
    """
    try:
        num_pct = ((number2 - number1) / number1) * 100
        return "{0:.{prec}f}%".format(num_pct, prec=precision)
    except ZeroDivisionError:
        return "{0:.{prec}f}%".format(0, prec=precision)