You will need to
know "the basis", what you originally paid. You can go online for historical information on stocks.
(Follow this link for the historical information on HP: http://h30261.www3.hp.com/stock/historical-lookup.aspx) It is acceptable to take the high and low price
of a stock and average them to arrive at a value.
Having some "best efforts" cost basis figure is better than not having anything at all.
The following
TurboTax information may be helpful in finding your cost basis.
https://ttlc.intuit.com/questions/1899678-how-do-i-find-a-stock-s-cost-basis
