Please answer the given financial question based on the context.
Context: notes to consolidated financial statements ( continued ) note 8 2014shareholders 2019 equity ( continued ) the following table summarizes activity in other comprehensive income related to derivatives , net of taxes , held by the company ( in millions ) : .
||2006|2005|2004|
|changes in fair value of derivatives|$ 11|$ 7|$ -21 ( 21 )|
|adjustment for net losses realized and included in net income|-12 ( 12 )|1|33|
|change in unrealized gain/loss on derivative instruments|$ -1 ( 1 )|$ 8|$ 12|
the tax effect related to the changes in fair value of derivatives was $ ( 8 ) million , $ ( 3 ) million , and $ 10 million for 2006 , 2005 , and 2004 , respectively . the tax effect related to derivative gains/losses reclassified from other comprehensive income to net income was $ 8 million , $ ( 2 ) million , and $ ( 13 ) million for 2006 , 2005 , and 2004 , respectively . employee benefit plans 2003 employee stock plan the 2003 employee stock plan ( the 201c2003 plan 201d ) is a shareholder approved plan that provides for broad- based grants to employees , including executive officers . based on the terms of individual option grants , options granted under the 2003 plan generally expire 7 to 10 years after the grant date and generally become exercisable over a period of 4 years , based on continued employment , with either annual or quarterly vesting . the 2003 plan permits the granting of incentive stock options , nonstatutory stock options , restricted stock units , stock appreciation rights , and stock purchase rights . 1997 employee stock option plan in august 1997 , the company 2019s board of directors approved the 1997 employee stock option plan ( the 201c1997 plan 201d ) , a non-shareholder approved plan for grants of stock options to employees who are not officers of the company . based on the terms of individual option grants , options granted under the 1997 plan generally expire 7 to 10 years after the grant date and generally become exercisable over a period of 4 years , based on continued employment , with either annual or quarterly vesting . in october 2003 , the company terminated the 1997 employee stock option plan and cancelled all remaining unissued shares totaling 28590702 . no new options can be granted from the 1997 plan . employee stock option exchange program on march 20 , 2003 , the company announced a voluntary employee stock option exchange program ( the 201cexchange program 201d ) whereby eligible employees , other than executive officers and members of the board of directors , had an opportunity to exchange outstanding options with exercise prices at or above $ 12.50 per share for a predetermined smaller number of new stock options issued with exercise prices equal to the fair market value of one share of the company 2019s common stock on the day the new awards were issued , which was to be at least six months plus one day after the exchange options were cancelled . on april 17 , 2003 , in accordance with the exchange program , the company cancelled options to purchase 33138386 shares of its common stock . on october 22 , 2003 , new stock options totaling 13394736 shares were issued to employees at an exercise price of $ 11.38 per share , which is equivalent to the closing price of the company 2019s stock on that date . no financial or accounting impact to the company 2019s financial position , results of operations or cash flows was associated with this transaction. .
Question: what was the greatest annual change in unrealized gain/loss on derivative instruments , in millions?/
Answer:
12.0