In some annuities, the index-linked interest rate is computed by subtracting a specific percentge from any calculated change in the index. This percentage, sometimes referred to as the “margin” or “spread” might be used instead of, or in addition to, a participation rate. For example, if the calculated change in the index is 10%, the annuity might specify that 2.25% will be subtracted from the rate to determine the interest rate credited. Here, the rate would be 7.75% (10% – 2.23% = 7.75%). In this example, the company subtracts the percentage only if the change in the index produces a positive interest rate.