private void awardBonus() {
                BigInteger bonusReduction = BigInteger.valueOf(100);
                for (int i=start; i<end; i++) {
                    BankAccount currentAccount = accounts.get(i);
                    if (currentAccount.getBalance().signum() > 0)
                        currentAccount.deposit(currentAccount.getBalance().divide(bonusReduction));
                }
            }