9 The Commissioner had, however, published a standard form by which the amount under s 21(3) was to be calculated and claimed. The form required the making of a statutory declaration including various figures by which the concession was calculated. The information needed to be provided in the statutory declaration will be known to the developer or vendor of an "off the plan" property sale rather than the purchaser. Mr Henderson made such a declaration on behalf of the vendor in respect of the apartment purchased by Mr and Mrs Frost. The declaration identified $521,660.92 as the cost of the works that occurred before the contract, being 16.564% of the construction works. It also identified $2,627,665.10 as the cost of the works to be completed after the contract date, being 83.436% of the construction works. The sum of these two amounts is $3,149,326.02 rather than the contract price itself. That is because the calculation initially required the exclusion of GST, the "off the plan land value" of the lot and the "non deductible costs" referable to the dutiable property. The declaration identified the GST inclusive amount for construction costs after the contract date to be $2,890,431.60 with, therefore, a dutiable value of $1,709,568.40. Based upon the declaration the transfer was assessed to duty in the sum of $94,026 on 1 July 2008.