I need to perform the same function for each row in my spreadsheet. I have 30 rows in total

I am attempting to calculate and store the number of days absent for my employees - I can do it for one row (employee) but I have thirty employees:

function updateDaysAbsent() {

var ss = SpreadsheetApp.getActiveSpreadsheet();

var formSS = ss.getSheetByName("TRANSPORT"); //Form Sheet

var tValA = [[formSS.getRange("G4").getValue()]]; // Result 4 days absent

var aValA = [[formSS.getRange("E4").getValue()]]; // Result 1 more day absent (always either 1 or Zero)

  if(aValA == 1){  var snValA = formSS.getRange("G4"); // Old number of days absent 4    snValA.setValue(Number(tValA)+1); // Result 5 days absents}

var tAmt = formSS.getRange("B4"); // Cell that Changes aValA to 1 if entry is made

tAmt.setValue(""); // Reset to default absent at the end of everyday until entry made

}