21.   The indexes are then used by buyers of natural gas, including utilities.

22.   The index is used as a benchmark recommendation by fund managers.

23.   The market uses an index that measures the potential cost of disasters by state or region, and the option price is linked to the index.

24.   The index is used by emerging market funds as a guide in the allocation of assets worth billions of dollars.

25.   The index is used to calculate cost-of-living adjustments for Social Security and other federal benefits.

26.   The index is used to mark the salmon production of the previous year and to predict that of the upcoming season.

27.   The ministry said the changes have made the figures unreliable, and economists have shied away from using the index until historical data becomes available.

28.   The Richmond Fed survey uses diffusion indexes.

29.   To even broader effect, the index is used to adjust the personal exemption, standard deduction and tax brackets for US taxpayers.

30.   Using any index, of course, is far from perfect.