Tessa took out a $110,000 loan with a 9% interest rate, compounded semi-annually, to be repaid by (semi-annual) payments of $8,456.38 over 10 years. After the sixth payment, the interest rate lowered to 7% (compounded semi-annually), reducing the payments to $7,916.12. After the 14th payment, the interest rate increased to 12% (compounded semi annually). Tessa then made an extra payment of X in addition to her normal 14th payment. With this additional payment and the interest rate change, the quarterly payments became 7100.01. Calculate X.