This chart shows the growth of a one-time $100,000 investment over 18 years, based on different returns. Increasing annual returns from 4% to 5% would generate enough extra money to pay for three current semesters at an in-state public college. Improving returns from 4% to 6% would cover three semesters at a private college. Key takeaway: Even small increases in investment performance can make a big difference over time.