Seeking to present a more realistic picture of the economy, the government will release a new series of national accounts with 2011-12 as base year for computing the economic growth rate. The Gross Domestic Product (GDP) data based on the new series will be released for three consecutive years from 2011-12 in January next year. At present, the GDP is computed on 2004-05 base year. "The new series will better reflect the economy as it would include more sectors. However, it would be difficult to say whether there would be any significant change in growth rates for the previous years," National Statistical Commission Chairman Pronab Sen, who was associated with formulation of the new series, said. He further said that it may take about one year to ascertain about the change in growth rates of different sectors and economy as a whole based on the new series during the previous years. "As per the revision policy of the national accounts, the estimates for the year 2011-12, 2012-13 and 2013-14, due for release in January 2015, would have been the third revised estimates, second revised and first revised estimates, respectively," as official statement said. Since these estimates have been compiled afresh, these would be referred to as "New Series" Estimates, it added. The government will also be revising the base year for consumer price index (CPI), wholesale price index (WPI) and index of industrial production (IIP). The new series of IIP and WPI are likely to be released by March 2016. The growth in the new series of IIP and WPI would be incorporated in the provisional estimates of 2014-15, to be released in May 2016. The National Statistical Commission has suggested that the base year for computing national account should be revised every five years. The base year of the national accounts is changed periodically to take into account the structural changes which take place in the economy and to depict a true picture of the economy through macro aggregates. The first official estimates of national income were prepared by the Central Statistical Organisation (CSO) with base year 1948-49 for the estimates at constant prices. These estimates at constant (1948-49) prices along with the corresponding estimates at current prices and the accounts of the Public Authorities were published in the publication, 'Estimates of National Income' in 1956. With the gradual improvement in the availability of basic data over the years, a comprehensive review of methodology for national accounts statistics has constantly been undertaken with a view to updating the data base and shifting the base year to a more recent year. The base years of the National Accounts Statistics series have been shifted from 1948-49 to 1960-61 in August 1967; from 1960-61 to 1970-71 in January 1978; from 1970-71 to 1980-81 in February 1988; and from 1980-81 to 1993-94 in February 1999. Thereafter it was changed to 2004-05 in 2006.