You will need slightly more income in each year of your retirement primarily because of inflation, which causes the cost of living to rise over time. As prices for goods and services increase each year (including essentials like food, energy, and healthcare), your retirement income must also increase to maintain your purchasing power and standard of living. Additionally, certain expenses such as healthcare tend to rise as you age, requiring more funds. Furthermore, you may want to support family members or have increasing lifestyle costs over time, making it necessary for your income to grow yearly to cover these expenses comfortably.