В InternetExplorer скрипт выдает NaN в output

function amount() { 
  var slider = document.getElementById("slider").value; 
  document.getElementById("box").innerHTML = slider; 
} 
 
$(document).ready(function() { 
  var amount, result5, result10, result15, result20; 
 
  var calculatorBill = $('.calculator__bill'); 
  var calculatorTip = $('.calculator__tip'); 
  var calculatorResult5 = $('.calculator__result-5years'); 
  var calculatorResult10 = $('.calculator__result-10years'); 
  var calculatorResult20 = $('.calculator__result-20years'); 
  var tipAmount = $('.tip-amount'); 
 
  // RANGE FUNCTION 
  calculatorTip.on('change', function() { 
    if (calculatorBill.val() === '' || isNaN(calculatorBill.val())) {} else { 
      amount = calculatorBill.val() * 1; 
    } 
 
    tipAmount.html(calculatorTip.val()); 
    result5 = amount * 87.6914387; 
    result10 = amount * 264.070241; 
    result20 = amount * 1332.38162; 
    calculatorResult5.html(result5.toFixed().replace(/(\d{1,3})(?=((\d{3})*([^\d]|$)))/g, ' $1 ')); 
    calculatorResult10.html(result10.toFixed().replace(/(\d{1,3})(?=((\d{3})*([^\d]|$)))/g, ' $1 ')); 
    calculatorResult20.html(result20.toFixed().replace(/(\d{1,3})(?=((\d{3})*([^\d]|$)))/g, ' $1 ')); 
  }); 
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> 
<div class="calculator__mobile-visible"> 
  <output class="calculator__result-5years calculator">929 201</output><span class="calculator__rubls"></span> 
</div> 
<div class="calculator__mobile-visible"> 
  <output class="calculator__result-10years calculator">2 794 036</output><span class="calculator__rubls"></span> 
</div> 
<div class="calculator__mobile-visible"> 
  <output class="calculator__result-20years calculator">14 117 236</output><span class="calculator__rubls"></span> 
</div>