NORMDIST can not work.

[Evansy]

i write a demo by README sample.

<!-- Numeric -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/numeric/1.2.6/numeric.min.js"></script>
<!-- Numeral.js -->
<script src="https://cdnjs.cloudflare.com/ajax/libs/numeral.js/1.4.5/numeral.min.js"></script>
<!-- jStat -->
<script src="https://cdn.jsdelivr.net/jstat/latest/jstat.min.js"></script>

<!-- Finally add formula.js -->
<script src="local-formula-path/formula.js"></script>

<script>
    
        window.onload = function()
        {
            formulajs.NORMDIST(21.2366,formulajs.AVERAGE(22.3016,21.2366), formulajs.STDEV(22.3016,21.2366),1);
        }
    </script>

but throw an exception

Uncaught TypeError: Cannot read property 'normal' of undefined
    at Object.exports.NORM.DIST [as NORMDIST] (formula.js:6481)
    at window.onload (excel.html:25)

it seems to the exception because jstat..