What financial document helps track individual expenses over time?

An expense report is a financial document specifically designed to track individual expenses over time. It is typically organized to provide a detailed account of all expenditures, allowing individuals or businesses to monitor spending patterns effectively. By categorizing expenses—such as food, transportation, entertainment, and utilities—this report enables users to analyze their financial behavior, identify potential areas for savings, and ensure that they are staying within their budget.

In contrast, the other options serve different purposes. A balance sheet provides a snapshot of an entity's assets, liabilities, and equity at a specific point in time, rather than tracking ongoing expenses. A savings account statement summarizes the transactions and balance of a savings account but does not break down individual spending. A net worth statement shows the difference between what a person owns and what they owe, giving an overall financial picture rather than focusing on individual expenses. Thus, the expense report is distinctly suited for tracking and managing expenses over time, making it the correct choice.