JavaScript中特定列的显示总和

Question

我希望显示特定区域的金额总和。以下是我的代码以显示数据，但是我确定如何将金额相加。我能够读取csv文件在html表中的显示。我是Java语言的新手。任何进行的帮助将不胜感激

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<script type="text/javascript">
 function loadFile(o)
   
     var fr = new FileReader();
     fr.onload = function(e)
      
        showDataFile(e, o);
      ;
    fr.readAsText(o.files[0]);
   

 function showDataFile(e, o)
   
    var getCSVData = e.target.result;
    var rows = getCSVData.split("\n");
    var html = '<table border="1">';
    rows.forEach((data, index) => 
    
       html += "<tr>";
       var value = data.split(",");
       var region = value[1];
       var amount =value[3];
        if(region=="SA")
          
             html += "<td>" + region + "</td>";
             html += "<td>" + amount + "</td>"
          
       html += "</tr>";
    );
         html += '</table>';  
         document.getElementById("data").innerHTML = html;
         document.getElementById("data").style.color="blue";
   
   </script>
   <title> Read CSV file using JavaScript  </title>
   </head>
   <body>
    Select file to read <input type="file" onchange="loadFile(this)">
    <pre id="data"></pre>
   </body>
  </html>