our tax returns are currently under examination in various foreign jurisdictions . the major foreign tax jurisdictions under examination include germany , italy and switzerland . it is reasonably possible that such audits will be resolved in the next twelve months , but we do not anticipate that the resolution of these audits would result in any material impact on our results of operations or financial position . 12 . capital stock and earnings per share we have 2 million shares of series a participating cumulative preferred stock authorized for issuance , none of which were outstanding as of december 31 , 2007 . the numerator for both basic and diluted earnings per share is net earnings available to common stockholders . the denominator for basic earnings per share is the weighted average number of common shares outstanding during the period . the denominator for diluted earnings per share is weighted average shares outstanding adjusted for the effect of dilutive stock options and other equity awards . the following is a reconciliation of weighted average shares for the basic and diluted share computations for the years ending december 31 ( in millions ) : .

Table:
 | 2007 | 2006 | 2005
weighted average shares outstanding for basic net earnings per share | 235.5 | 243.0 | 247.1
effect of dilutive stock options and other equity awards | 2.0 | 2.4 | 2.7
weighted average shares outstanding for diluted net earnings per share | 237.5 | 245.4 | 249.8
weighted average shares outstanding for basic net earnings per share 235.5 243.0 247.1 effect of dilutive stock options and other equity awards 2.0 2.4 2.7 weighted average shares outstanding for diluted net earnings per share 237.5 245.4 249.8 for the year ended december 31 , 2007 , an average of 3.1 million options to purchase shares of common stock were not included in the computation of diluted earnings per share as the exercise prices of these options were greater than the average market price of the common stock .
for the years ended december 31 , 2006 and 2005 , an average of 7.6 million and 2.9 million options , respectively , were not included .
in december 2005 , our board of directors authorized a stock repurchase program of up to $ 1 billion through december 31 , 2007 .
in december 2006 , our board of directors authorized an additional stock repurchase program of up to $ 1 billion through december 31 , 2008 .
as of december 31 , 2007 we had acquired approximately 19345200 shares at a cost of $ 1378.9 million , before commissions .
13 .
segment data we design , develop , manufacture and market reconstructive orthopaedic implants , including joint and dental , spinal implants , trauma products and related orthopaedic surgical products which include surgical supplies and instruments designed to aid in orthopaedic surgical procedures and post-operation rehabilitation .
we also provide other healthcare related services .
revenue related to these services currently represents less than 1 percent of our total net sales .
we manage operations through three major geographic segments 2013 the americas , which is comprised principally of the united states and includes other north , central and south american markets ; europe , which is comprised principally of europe and includes the middle east and africa ; and asia pacific , which is comprised primarily of japan and includes other asian and pacific markets .
this structure is the basis for our reportable segment information discussed below .
management evaluates operating segment performance based upon segment operating profit exclusive of operating expenses pertaining to global operations and corporate expenses , share-based compensation expense , settlement , acquisition , integration and other expenses , inventory step-up , in-process research and development write- offs and intangible asset amortization expense .
global operations include research , development engineering , medical education , brand management , corporate legal , finance , and human resource functions , and u.s .
and puerto rico based manufacturing operations and logistics .
intercompany transactions have been eliminated from segment operating profit .
management reviews accounts receivable , inventory , property , plant and equipment , goodwill and intangible assets by reportable segment exclusive of u.s and puerto rico based manufacturing operations and logistics and corporate assets .
z i m m e r h o l d i n g s , i n c .
2 0 0 7 f o r m 1 0 - k a n n u a l r e p o r t notes to consolidated financial statements ( continued ) .

Question: what is the change in weighted average shares outstanding for diluted net earnings per share between 2006 and 2007 , in millions?
Answer: -7.9
Calculation: subtract(237.5, 245.4)