Benford's Law is a probability rule frequently used by accounting auditors to detect systematic fraud. It states that approximately 19.9% of numbers will begin with the number 2. An auditor decides to investigate a particular firm further if a sample proportion of their invoices, with the invoiced number beginning with a 2, is in the highest 0.5% of all possible sample proportions. What sample proportion will cause further investigation of the firm if a random sample of 534 invoices is selected? Express your answer in decimal form (ie not as a percentage), correct to two decimal places