The growth estimates for the October-December quarter (Q3), in a range of 7.0%-8.1%, are based on old GDP series, with base year 2011-12. The data, due out on 27 February, will see updated GDP series with base year shifting to 2022-23. The move could lead to an overhaul of GDP calculations, raising the possibility of divergence from official growth figures for technical reasons, the economists polled by Mint said.