notes to consolidated financial statements ( continued ) note 6 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 ) : .
[['', '2007', '2006', '2005'], ['changes in fair value of derivatives', '$ -1 ( 1 )', '$ 11', '$ 7'], ['adjustment for net ( losses ) /gains realized and included in net income', '-2 ( 2 )', '-12 ( 12 )', '1'], ['change in unrealized gains on derivative instruments', '$ -3 ( 3 )', '$ -1 ( 1 )', '$ 8']]
the tax effect related to the changes in fair value of derivatives was $ 1 million , $ ( 8 ) million , and $ ( 3 ) million for 2007 , 2006 , and 2005 , respectively .the tax effect related to derivative gains/losses reclassified from other comprehensive income to net income was $ 2 million , $ 8 million , and $ ( 2 ) million for 2007 , 2006 , and 2005 , respectively .employee benefit plans 2003 employee stock plan the 2003 employee stock plan ( the 2018 20182003 plan 2019 2019 ) 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 four years , based on continued employment , with either annual or quarterly vesting .the 2003 plan permits the granting of incentive stock options , nonstatutory stock options , rsus , stock appreciation rights , stock purchase rights and performance-based awards .during 2007 , the company 2019s shareholders approved an amendment to the 2003 plan to increase the number of shares authorized for issuance by 28 million shares .1997 employee stock option plan in august 1997 , the company 2019s board of directors approved the 1997 employee stock option plan ( the 2018 20181997 plan 2019 2019 ) , 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 four years , based on continued employment , with either annual or quarterly vesting .in october 2003 , the company terminated the 1997 plan and no new options can be granted from this plan .1997 director stock option plan in august 1997 , the company 2019s board of directors adopted a director stock option plan ( the 2018 2018director plan 2019 2019 ) for non-employee directors of the company , which was approved by shareholders in 1998 .pursuant to the director plan , the company 2019s non-employee directors are granted an option to acquire 30000 shares of common stock upon their initial election to the board ( 2018 2018initial options 2019 2019 ) .the initial options vest and become exercisable in three equal annual installments on each of the first through third anniversaries of the grant date .on the fourth anniversary of a non-employee director 2019s initial election to the board and on each subsequent anniversary thereafter , the director will be entitled to receive an option to acquire 10000 shares of common stock ( 2018 2018annual options 2019 2019 ) .annual options are fully vested and immediately exercisable on their date of grant .rule 10b5-1 trading plans certain of the company 2019s executive officers , including mr .timothy d .cook , mr .peter oppenheimer , mr .philip w .schiller , and dr .bertrand serlet , have entered into trading plans pursuant to .

Question: what was the change in unrealized gains on derivative instruments between 2006 and 2007?
Answer: 2