In computing the total income of an assessee, being an individual or a Hindu undivided family, there shall be deducted, the whole of the amount, to the extent such amount does not exceed twenty thousand rupees, paid or deposited, during the previous year relevant to the assessment year beginning on the 1st day of April, 2011or to the assessment year beginning on the 1st day of April, 2012, as subscription to long-term infrastructure bonds as may, for the purposes of this section, be notified by the Central Government.