Section 591.224 - How does OPM adjust price indexes between surveys?(a) OPM adjusts price indexes between the triennial surveys in each COLA area that is not surveyed in that year. To do this, OPM uses the annual or biennial change in the Consumer Price Index (CPI) for the COLA area relative to the annual or biennial change in the CPI for the Washington, DC, area. OPM uses the annual change for those areas surveyed the preceding year. OPM uses the biennial change for those areas surveyed 2 years before.(b) Paragraph (a) of this section applies beginning with the effective date of the results of the 2005 survey conducted in Puerto Rico and the U.S. Virgin Islands.(c) Based on additional housing data that may be collected before the 2005 survey conducted in Puerto Rico and the U.S. Virgin Islands, OPM will adjust as warranted the price indexes and COLA rates for Puerto Rico, the U.S. Virgin Islands, and the COLA areas in the State of Alaska. OPM will implement any such adjustments on a one-time basis on the effective date of the results of the 2004 surveys conducted in Hawaii and Guam/CNMI, and subject to § 591.228 . OPM will publish such adjustments as provided in § 591.229 .67 FR 22340, May 3, 2002, as amended at 69 FR 59763, Oct. 6, 2004