The much-anticipated back series data of gross domestic product (GDP) of India would now be released by the end of December as the policy think tank Niti Aayog has sought more time to analyse and recalculate the growth estimates. The government had earlier set an internal deadline of November for the revised estimates of GDP growth from 2004\u20132005 to 2011-2012 and was expected to announce it on Monday. In the last moment decision on Monday, Niti Aayog said that a roundtable discussion was held under the chairmanship of Rajiv Kumar, vice-chairman, of NITI Aayog, for the purpose.\u00a0\u201cDuring the ensuing discussion, experts sought analytical information, which is being worked out. It was, therefore decided to have a follow-up roundtable discussion with experts shortly,\u201d Anna Roy, Adviser (Data Management & Analysis) at NITI Aayog said in a statement. Also Read:\u00a0Modi\u2019s village electrification is among world\u2019s biggest successes this year, says this report The government in January 2015 had decided to change the base year of 2004-05 for national accounts to new base year of 2011-12. The base year had been revised earlier in January 2010. The Central Statistics Office (CSO) therefore in the new series did away with GDP at factor cost, while adopting global practices of valuing industry-wise estimates as GVA (gross value added) at current or basic prices. With the change in the base year, the GDP growth for the financial year 2013-14 was estimated at 6.9% as compared with 4.7% on the 2004-05 base year. Similarly, the growth rate for 2012-13 was also revised from 4.5% to 5.1%. However, for the years preceding fiscal 2011-12, CSO faced difficulties while evaluating growth rate of the economy with the new base year, mainly on account of lack of availability of MCA-21 database. The then Chief Statistician of India T C A Anant also stated in 2017 that they are facing a major statistical challenge while analysing back series due to the unavailability of data from earlier years. The back series GDP data is being widely anticipated as a Committee on Real Sector Statistics, appointed by the National Statistical Commission (NSC), the autonomous body that helps in data collection by India\u2019s statistical agencies, had said in a report that the Indian economy grew at a faster pace from 2004-05 to 2013-14, compared with the average growth during the first four years of the present government.