z i m m e r h o l d i n g s , i n c . a n d s u b s i d i a r i e s 2 0 0 3 f o r m 1 0 - k the following table sets forth the operating profit margin by cost of products sold . included in cost of product sold are segment for the years ended december 31 , 2003 , losses on foreign exchange hedge contracts , which increased 2002 and 2001 : in 2003 relative to 2002 . in the fourth quarter , the company reported operating profit as a percent of net sales of percent of net sales 47.1 percent for asia pacific. .

1	year ended december 31,	2003	2002	2001
2	americas	51.2% ( 51.2 % )	48.3% ( 48.3 % )	47.4% ( 47.4 % )
3	europe	26.3	24.4	19.5
4	asia pacific	45.3	46.1	45.4

operating profit for the americas as a percentage of net sales increased to 48.3 percent in 2002 from 47.4 percent in year ended december 31 , 2003 2001 , reflecting improved gross profit margins due to higher compared to year ended december 31 , 2002 average selling prices and increased sales of higher margin operating profit for the americas as a percentage of net products , and lower selling expenses as a percent of sales sales increased due to improved gross margins driven by due to lower costs associated with the u.s . distributor higher average selling prices and increased sales of higher network . the americas continued to invest in strategic margin products , leveraged operating expenses and the initiatives such as mis technologies , field sales personnel , favorable impact of the change in accounting principle for medical education programs and new product launches . instruments . the change in accounting principle for operating profit for asia pacific as a percentage of net instruments increased operating profit by 1.7 percentage sales increased to 46.1 percent in 2002 from 45.4 percent points . with respect to sales growth , increased zimmer in 2001 . this increase reflects lower selling , general and standalone average selling prices of 4 percent in 2003 and administrative expenses as a percent of sales in japan as favorable effects of volume and mix , 15 percent increase in a result of a sales force and dealer reorganization , partially 2003 , represent the most significant factors in improved offset by lower gross profit margins as a result of lower yen operating profit in the americas . as reconstructive implant hedge gains compared to 2001 . sales grow at a higher rate than trauma and orthopaedic operating profit for europe as a percentage of net sales surgical products , operating profit margins generally tend to increased to 24.4 percent in 2002 from 19.5 percent in 2001 , improve since reconstructive product sales generally earn due to improved gross profit margins as a result of higher higher gross margins . this was the case in 2003 , with zimmer average selling prices and favorable product and country mix , standalone reconstructive implant sales growth of 22 percent the leveraging of sales growth in europe on controlled as compared with total zimmer standalone sales growth of increases in operating expenses and improved efficiency 19 percent . in the fourth quarter , the company reported in the utilization of instruments ( more frequent use of operating profit as a percent of net sales of 50.4 percent for instruments resulted in fewer placements and less expense ) . the americas . operating profit for europe as a percentage of net sales liquidity and capital resources increased due to improved gross profit margins driven by cash flows provided by operations were $ 494.8 million higher zimmer standalone average selling prices and in 2003 , compared with $ 220.2 million in 2002 . the principal favorable product and country mix , leveraged operating source of cash was net earnings before cumulative effect of expenses and the favorable impact of the change in change in accounting principle of $ 291.2 million . non-cash accounting principle for instruments . the change in expenses for the period included depreciation and accounting for instruments increased operating profit by amortization expense of $ 103.3 million , centerpulse inventory 1.4 percentage points . increases in zimmer standalone step-up of $ 42.7 million and centerpulse in-process research average selling prices in europe of 2 percent in 2003 and the and development write-offs of $ 11.2 million . working capital effect of volume and mix , 19 percent increase in 2003 , were management , together with the collection of $ 20.0 million of the key factors in improved operating profit . also cash related to centerpulse tax loss carryforwards , contributing to the improvement was significantly lower contributed $ 80.4 million to operating cash flow . growth in operating expenses . in the fourth quarter , the working capital continues to be a key management focus . company reported operating profit as a percent of net sales at december 31 , 2003 , the company had 62 days of sales of 24.7 percent for europe . outstanding in accounts receivable , unfavorable to the prior operating profit for asia pacific as a percentage of year by 10 days . acquired centerpulse businesses had a net sales decreased primarily due to less favorable rates on negative impact of 10 days , due to centerpulse 2019s business hedge contracts during the year compared to the prior year , mix which has a greater proportion of european revenue with partially offset by increased zimmer standalone average payment terms generally longer than those in the u.s . at selling prices and leveraged operating expenses . the change december 31 , 2003 , the company had 232 days of inventory in accounting for instruments had an immaterial effect on on hand compared to 247 days reported at the end of 2002 . operating profit for asia pacific . increases in zimmer the reduction was principally due to improved inventory standalone average selling prices in asia pacific of 1 percent management and the acquired dental and spinal businesses and volume and mix improvements of 4 percent in 2003 carrying fewer days of inventory . contributed modest improvement but was offset by higher .

Previous questions in this conversation: what was the operating profit for the americas as a percentage of net sales in 2003? and what was it in 2001?
Previous answers: 51.2 47.4
Question: by what amount, then, did it change over the years?
Answer: 3.8