liquidity and capital resources during the past three years , we had sufficient financial resources to meet our operating requirements , to fund our capital spending , share repurchases and pension plans and to pay increasing dividends to our shareholders . cash from operating activities was $ 1436 million , $ 1310 million , and $ 1345 million in 2011 , 2010 , and 2009 , respectively . higher earnings increased cash from operations in 2011 compared to 2010 , but the increase was reduced by cash used to fund an increase in working capital of $ 212 million driven by our sales growth in 2011 . cash provided by working capital was greater in 2009 than 2010 and that decline was more than offset by the cash from higher 2010 earnings . operating working capital is a subset of total working capital and represents ( 1 ) trade receivables-net of the allowance for doubtful accounts , plus ( 2 ) inventories on a first-in , first-out ( 201cfifo 201d ) basis , less ( 3 ) trade creditors 2019 liabilities . see note 3 , 201cworking capital detail 201d under item 8 of this form 10-k for further information related to the components of the company 2019s operating working capital . we believe operating working capital represents the key components of working capital under the operating control of our businesses . operating working capital at december 31 , 2011 and 2010 was $ 2.7 billion and $ 2.6 billion , respectively . a key metric we use to measure our working capital management is operating working capital as a percentage of sales ( fourth quarter sales annualized ) . ( millions ) 2011 2010 operating working capital $ 2739 $ 2595 operating working capital as % (  % ) of sales 19.5% ( 19.5 % ) 19.2% ( 19.2 % ) the change in operating working capital elements , excluding the impact of currency and acquisitions , was an increase of $ 195 million during the year ended december 31 , 2011 . this increase was the net result of an increase in receivables from customers associated with the 2011 increase in sales and an increase in fifo inventory slightly offset by an increase in trade creditors 2019 liabilities . trade receivables from customers , net , as a percentage of fourth quarter sales , annualized , for 2011 was 17.9 percent , down slightly from 18.1 percent for 2010 . days sales outstanding was 66 days in 2011 , level with 2010 . inventories on a fifo basis as a percentage of fourth quarter sales , annualized , for 2011 was 13.1 percent level with 2010 . inventory turnover was 5.0 times in 2011 and 4.6 times in 2010 . total capital spending , including acquisitions , was $ 446 million , $ 341 million and $ 265 million in 2011 , 2010 , and 2009 , respectively . spending related to modernization and productivity improvements , expansion of existing businesses and environmental control projects was $ 390 million , $ 307 million and $ 239 million in 2011 , 2010 , and 2009 , respectively , and is expected to be in the range of $ 450-$ 550 million during 2012 . capital spending , excluding acquisitions , as a percentage of sales was 2.6% ( 2.6 % ) , 2.3% ( 2.3 % ) and 2.0% ( 2.0 % ) in 2011 , 2010 and 2009 , respectively . capital spending related to business acquisitions amounted to $ 56 million , $ 34 million , and $ 26 million in 2011 , 2010 and 2009 , respectively . we continue to evaluate acquisition opportunities and expect to use cash in 2012 to fund small to mid-sized acquisitions , as part of a balanced deployment of our cash to support growth in earnings . in january 2012 , the company closed the previously announced acquisitions of colpisa , a colombian producer of automotive oem and refinish coatings , and dyrup , a european architectural coatings company . the cost of these acquisitions , including assumed debt , was $ 193 million . dividends paid to shareholders totaled $ 355 million , $ 360 million and $ 353 million in 2011 , 2010 and 2009 , respectively . ppg has paid uninterrupted annual dividends since 1899 , and 2011 marked the 40th consecutive year of increased annual dividend payments to shareholders . we did not have a mandatory contribution to our u.s . defined benefit pension plans in 2011 ; however , we made voluntary contributions to these plans in 2011 totaling $ 50 million . in 2010 and 2009 , we made voluntary contributions to our u.s . defined benefit pension plans of $ 250 and $ 360 million ( of which $ 100 million was made in ppg stock ) , respectively . we expect to make voluntary contributions to our u.s . defined benefit pension plans in 2012 of up to $ 60 million . contributions were made to our non-u.s . defined benefit pension plans of $ 71 million , $ 87 million and $ 90 million ( of which approximately $ 20 million was made in ppg stock ) for 2011 , 2010 and 2009 , respectively , some of which were required by local funding requirements . we expect to make mandatory contributions to our non-u.s . plans in 2012 of approximately $ 90 million . the company 2019s share repurchase activity in 2011 , 2010 and 2009 was 10.2 million shares at a cost of $ 858 million , 8.1 million shares at a cost of $ 586 million and 1.5 million shares at a cost of $ 59 million , respectively . we expect to make share repurchases in 2012 as part of our cash deployment focused on earnings growth . the amount of spending will depend on the level of acquisition spending and other uses of cash , but we currently expect to spend in the range of $ 250 million to $ 500 million on share repurchases in 2012 . we can repurchase about 9 million shares under the current authorization from the board of directors . 26 2011 ppg annual report and form 10-k .

========================================
• ( millions ), 2011, 2010, 
• operating working capital, $ 2739, $ 2595, 
• operating working capital as % (  % ) of sales, 19.5% ( 19.5 % ), 19.2, % (  % )
========================================

liquidity and capital resources during the past three years , we had sufficient financial resources to meet our operating requirements , to fund our capital spending , share repurchases and pension plans and to pay increasing dividends to our shareholders . cash from operating activities was $ 1436 million , $ 1310 million , and $ 1345 million in 2011 , 2010 , and 2009 , respectively . higher earnings increased cash from operations in 2011 compared to 2010 , but the increase was reduced by cash used to fund an increase in working capital of $ 212 million driven by our sales growth in 2011 . cash provided by working capital was greater in 2009 than 2010 and that decline was more than offset by the cash from higher 2010 earnings . operating working capital is a subset of total working capital and represents ( 1 ) trade receivables-net of the allowance for doubtful accounts , plus ( 2 ) inventories on a first-in , first-out ( 201cfifo 201d ) basis , less ( 3 ) trade creditors 2019 liabilities . see note 3 , 201cworking capital detail 201d under item 8 of this form 10-k for further information related to the components of the company 2019s operating working capital . we believe operating working capital represents the key components of working capital under the operating control of our businesses . operating working capital at december 31 , 2011 and 2010 was $ 2.7 billion and $ 2.6 billion , respectively . a key metric we use to measure our working capital management is operating working capital as a percentage of sales ( fourth quarter sales annualized ) . ( millions ) 2011 2010 operating working capital $ 2739 $ 2595 operating working capital as % (  % ) of sales 19.5% ( 19.5 % ) 19.2% ( 19.2 % ) the change in operating working capital elements , excluding the impact of currency and acquisitions , was an increase of $ 195 million during the year ended december 31 , 2011 . this increase was the net result of an increase in receivables from customers associated with the 2011 increase in sales and an increase in fifo inventory slightly offset by an increase in trade creditors 2019 liabilities . trade receivables from customers , net , as a percentage of fourth quarter sales , annualized , for 2011 was 17.9 percent , down slightly from 18.1 percent for 2010 . days sales outstanding was 66 days in 2011 , level with 2010 . inventories on a fifo basis as a percentage of fourth quarter sales , annualized , for 2011 was 13.1 percent level with 2010 . inventory turnover was 5.0 times in 2011 and 4.6 times in 2010 . total capital spending , including acquisitions , was $ 446 million , $ 341 million and $ 265 million in 2011 , 2010 , and 2009 , respectively . spending related to modernization and productivity improvements , expansion of existing businesses and environmental control projects was $ 390 million , $ 307 million and $ 239 million in 2011 , 2010 , and 2009 , respectively , and is expected to be in the range of $ 450-$ 550 million during 2012 . capital spending , excluding acquisitions , as a percentage of sales was 2.6% ( 2.6 % ) , 2.3% ( 2.3 % ) and 2.0% ( 2.0 % ) in 2011 , 2010 and 2009 , respectively . capital spending related to business acquisitions amounted to $ 56 million , $ 34 million , and $ 26 million in 2011 , 2010 and 2009 , respectively . we continue to evaluate acquisition opportunities and expect to use cash in 2012 to fund small to mid-sized acquisitions , as part of a balanced deployment of our cash to support growth in earnings . in january 2012 , the company closed the previously announced acquisitions of colpisa , a colombian producer of automotive oem and refinish coatings , and dyrup , a european architectural coatings company . the cost of these acquisitions , including assumed debt , was $ 193 million . dividends paid to shareholders totaled $ 355 million , $ 360 million and $ 353 million in 2011 , 2010 and 2009 , respectively . ppg has paid uninterrupted annual dividends since 1899 , and 2011 marked the 40th consecutive year of increased annual dividend payments to shareholders . we did not have a mandatory contribution to our u.s . defined benefit pension plans in 2011 ; however , we made voluntary contributions to these plans in 2011 totaling $ 50 million . in 2010 and 2009 , we made voluntary contributions to our u.s . defined benefit pension plans of $ 250 and $ 360 million ( of which $ 100 million was made in ppg stock ) , respectively . we expect to make voluntary contributions to our u.s . defined benefit pension plans in 2012 of up to $ 60 million . contributions were made to our non-u.s . defined benefit pension plans of $ 71 million , $ 87 million and $ 90 million ( of which approximately $ 20 million was made in ppg stock ) for 2011 , 2010 and 2009 , respectively , some of which were required by local funding requirements . we expect to make mandatory contributions to our non-u.s . plans in 2012 of approximately $ 90 million . the company 2019s share repurchase activity in 2011 , 2010 and 2009 was 10.2 million shares at a cost of $ 858 million , 8.1 million shares at a cost of $ 586 million and 1.5 million shares at a cost of $ 59 million , respectively . we expect to make share repurchases in 2012 as part of our cash deployment focused on earnings growth . the amount of spending will depend on the level of acquisition spending and other uses of cash , but we currently expect to spend in the range of $ 250 million to $ 500 million on share repurchases in 2012 . we can repurchase about 9 million shares under the current authorization from the board of directors . 26 2011 ppg annual report and form 10-k .

Question: if trade receivables from customers trends at the same rate as 2011 , what will the 2012 allowance be as a percentage of fourth quarter sales?
Program: subtract(17.9, 18.1), subtract(17.9, #0)
Answer: 18.1