Isaac Inc. began operations in January 2021. For some property sales, Isaac recognizes income in the period of sale for financial reporting purposes. However, for income tax purposes, Isaac recognizes income when it collects cash from the buyer's installment payments. In 2021, Isaac had $600 million in sales of this type. Scheduled collections for these sales are as follows: 2021 $ 60 million 2022 120 million 2023 120 million 2024 150 million 2025 150 million $ 600 million Assume that Isaac has a 25% income tax rate and that there were no other differences in income for financial statement and tax purposes.

1. What is the income tax expense for each year?