void incrementColumnValues(String columnName, Delta delta, int headerRowIndex) throws InvalidInputException {
int columnNumber = columnNumberContainingText(columnName, headerRowIndex);
int totalNumberOfRows = numberOfRows();
for (int i = headerRowIndex + 2; i < totalNumberOfRows; ++i) {
Parse columnToBeUpdated = table.at(0, i, columnNumber);
String value = columnToBeUpdated.text();
value = delta.addTo(value, i - headerRowIndex - 1);
columnToBeUpdated.body = value;
}
}