"The average size of the households is about 5 people and in most, not more than one person may be the earning member. In addition, various exemptions and deductions are allowed to different categories of taxpayers, which also reduces the tax base. Taking into account the above facts, it was felt that the maximum tax base would not be more than 5 per cent of the population," the finance ministry said in a statement tabled on Friday in the Lok Sabha.

The statement was on the status of the implementation of report of the standing committee on finance, relating to the revenue department.

The ministry also said the tax-GDP ratio of the Centre was projected to reach 11.2 per cent in the current fiscal. The increase in the ratio was mainly on account of the rationalisation and removal of tax exemptions and concessions laid down in the Income Tax Act, it said.

It added that a white paper on information technology in tax administration would soon be submitted to the standing committee.

"The department is continuously reviewing all deductions and concessions and wherever such concessions are found to have outlived their utility and economic rationale, they would be either removed or rationalised," the ministry said.

Admitting that 61 per cent of the transactions reported in the annual information returns (did not contain a permanent account number, the ministry said several measures had been initiated to address the issue.

Also, the initial low compliance by sub-registrars of property in filing AIR had been addressed after the matter was taken up with the state governments.

The number of registrars and sub-registrars who have filed AIRs has increased to 1,170 on March 15, compared to 372 on December 7 last year against a total number of 3,626 registrars and sub-registrars in the country, it said.

The ministry also said while it had accepted, in principle, the suggestion of the committee to increase the percentage of scrutiny beyond the present ceiling of two per cent, it was not possible to implement the same in view of the acute shortage of manpower in the income tax department.