time series analysis of financial statements covering more than one accounting period; also called TREND ANALYSIS. It looks at the percentage change in an account over time. The percentage change equals the change over the prior year. For example, if sales in 20X0 are $100,000 and in 20X1 are $300,000, there is a 200% increase ($200,000/$100,000). By examining the magnitude of direction of a financial statement item over time, the analyst can evaluate its reasonableness.