Macy reported sales of $8 million and net income of $1.5 million. The firm has $10.5 million in total assets and $1 million in current liabilities. The firm currently pays out 75% of its net income to shareholders. Assume that all assets and current liabilities are expected to grow with sales. If Macy does not want to rely on any external source of funds, what is the most sales can grow (in percent)?