 The IPD Annual Index covers approximately 12,000 directly held UK property investments, market revalued in December 2015 at just under £202 billion equivalent to 49% of the UK investment market.IPD indices have also been used in a number of other countries such as Australia, France, Germany, Italy, Japan and Switzerland as the basis for commercial property derivatives.In the United States commercial property utilizes the National Council of Real Estate Investment Fiduciaries (NCREIF) property index the NPI.