Betty earns $100,000 working as a part time lawyer in New Orleans. The company provides a matching contribution in the 401(k) plan of 50% up to a maximum contribution of 4% of compensation. Her 401(k) plan account had $60,000 in it at the beginning of the year. She contributed $15,000 to the plan this year and the employer made the matching contribution before year-end. The ending balance of the account is $100,000. What is her return on investments this year?