Consolidated audited financial statements received before the end of March 1998 were used. For certain companies with financial year-ends towards the end of the calendar year, statistics may thus refer to financial years ended during 1997.
Investments are at market price or directors' valuation, at latest balance sheet date.
Other assets, such as land and buildings, are at book value. Where revaluations were not taken into the balance sheet, these were ignored. Where cash balances were netted off against bank overdraft, the cash balances were added back. Tax paid in advance was netted off against tax payable, and only the gross amount included. If stock was valued using Lifo, it was adjusted to reflect the Fifo or average value if this was disclosed.