Send an email after multiple rows have been updated

Question

I've been using the below script which is working fine, however I'd like to cut down on the number of times it triggers.

function sendNotification(event) {
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  //var sheet = ss.getSheetByName("Allocation Requests");
  var sheet = ss.getActiveSheet();
  var row = sheet.getActiveRange().getRow();
  var cellvalue = ss.getActiveCell().getValue().toString();
  var emailAdd = "email@yourdomain.com";
  if(event.range.getA1Notation().indexOf("G") > -1 && sheet.getRange("G" + row).getDisplayValue() && emailAdd.length > 1)
  {
    {var confirm = Browser.msgBox('Case Quantity', 'Is this a confirmed amount?', Browser.Buttons.YES_NO); 
  if(confirm!='yes'){return};
     var rowVals = getActiveRowValues(sheet);
     MailApp.sendEmail({
       to: emailAdd,
       subject: "Allocation Request - " + rowVals.quantity + " cases on " + rowVals.date,
       htmlBody: "There has been a new allocation request from " + rowVals.name + " in the " + rowVals.team + " team.<br \> <br \> " 
       + "<table border = \"1\" cellpadding=\"10\" cellspacing=\"0\"><tr><th>Issuing Depot</th><th>Delivery Date</th><th>Case Quantity</th></tr><tr><td>"+rowVals.depot+"</td><td>"+rowVals.date+"</td><td>"+rowVals.quantity+"</td></tr></table>" 

      });
  }
}


/**
* get values of depot, date, quantity and name from their respective cells.
* @returns    {Object.<string, string>}
*/
function getActiveRowValues(sheet){
  var cellRow = sheet.getActiveRange().getRow();
  // get depot value
  var depotCell = sheet.getRange("E" + cellRow);
  var depot = depotCell.getDisplayValue();
  // get date value
  var dateCell = sheet.getRange("F" + cellRow);
  var date = dateCell.getDisplayValue();
  // get quantity value
  var quantCell = sheet.getRange("G" + cellRow);
  var quant = quantCell.getDisplayValue();
  // return an object with your values
  var nameCell = sheet.getRange("B" + cellRow);
  var name = nameCell.getDisplayValue();
  var teamCell = sheet.getRange("C" + cellRow);
  var team = teamCell.getDisplayValue();
  return {
    depot: depot,
    date: date,
    quantity: quant,
    name: name,
    team: team
  } }
}

Users enter more than one row of data at a time, and I would like to receive a notification when that user has finished entering data, but still send the information in the email for all the rows they've entered. At present I get an email each time they complete a row.