A couple can draw an additional fund of $3.12 million through the home equity line of credit. Understanding that they have gone through a mortgage loan under the loan-to-value ratio (LTV) of 60% for their home 10 years ago and the value of their flat has appreciated 2% annually. If they are still owing the original mortgage of 2 million and the government has released the LTV to 70%, how much did they borrow?