RF Corporation is using $77 million in Retained Earnings to fund a new project. Given that its Common Stock is currently selling at $353 per share, paying dividends of $43 per year, while the company is growing at 7% per year and its aggregate corporate tax rate for this company is 36%, compute the after tax cost of capital for this corporation's usage of Retained Earnings.

Write your answer as percentage (e.g. if your answer is 5%, write 5 not 0.05).