In 2020, a certain company's net income was $400,000. Their net income is projected to increase by 15 % each year. This can be modeled by f(x) = 400,000(1+0.15), where x is the number of years since 2020. How many years after 2020 will the company's net income be $3,600,000? Round your answer to the nearest tenth, if necessary.