{"pre_text": ["operating expenses as a percentage of total revenue ."], "post_text": ["operating expense summary 2006 compared to 2005 overall operating expenses increased $ 122.5 million in 2006 , as compared to 2005 , primarily due to : 2022 an increase of $ 58.4 million in stock-based compensation expense due to our adoption of sfas no .", "123r ; and 2022 an increase of $ 49.2 million in salary , benefits and other employee-related costs , primarily due to an increased number of employees and increases in bonus and commission costs , in part due to our acquisition of verisity ltd. , or verisity , in the second quarter of 2005 .", "2005 compared to 2004 operating expenses increased $ 97.4 million in 2005 , as compared to 2004 , primarily due to : 2022 an increase of $ 63.3 million in employee salary and benefit costs , primarily due to our acquisition of verisity and increased bonus and commission costs ; 2022 an increase of $ 9.9 million in stock-based compensation expense due to grants of restricted stock and the assumption of options in our acquisitions ; 2022 an increase of $ 8.6 million in losses associated with the sale of installment contract receivables ; and 2022 an increase of $ 7.1 million in costs related to the retirement of our executive chairman and former president and chief executive officer in 2005 ; partially offset by 2022 our restructuring activities , as discussed below .", "marketing and sales 2006 compared to 2005 marketing and sales expenses increased $ 39.4 million in 2006 , as compared to 2005 , primarily due to : 2022 an increase of $ 14.8 million in stock-based compensation expense due to our adoption of sfas no .", "123r ; 2022 an increase of $ 18.2 million in employee salary , commissions , benefits and other employee-related costs due to increased hiring of sales and technical personnel , and higher commissions earned resulting from an increase in 2006 sales performance ; and 2022 an increase of $ 7.8 million in marketing programs and customer-focused conferences due to our new marketing initiatives and increased travel to visit our customers .", "2005 compared to 2004 marketing and sales expenses increased $ 33.1 million in 2005 , as compared to 2004 , primarily due to : 2022 an increase of $ 29.4 million in employee salary , commission and benefit costs due to increased hiring of sales and technical personnel and higher employee bonuses and commissions ; and 2022 an increase of $ 1.6 million in stock-based compensation expense due to grants of restricted stock and the assumption of options in our acquisitions ; partially offset by 2022 a decrease of $ 1.9 million in marketing program costs. ."], "table": [["", "2006", "2005", "2004"], ["marketing and sales", "27% ( 27 % )", "28% ( 28 % )", "28% ( 28 % )"], ["research and development", "31% ( 31 % )", "29% ( 29 % )", "31% ( 31 % )"], ["general and administrative", "10% ( 10 % )", "10% ( 10 % )", "7% ( 7 % )"]], "table_ori": [["", "2006", "2005", "2004"], ["Marketing and sales", "27%", "28%", "28%"], ["Research and development", "31%", "29%", "31%"], ["General and administrative", "10%", "10%", "7%"]]}

Question: what was the change in research and development expenses as a percentage of total revenue from 2005 to 2006?
Evidence:
table_2: the research and development of 2006 is 31% ( 31 % ) ; the research and development of 2005 is 29% ( 29 % ) ; the research and development of 2004 is 31% ( 31 % ) ;
Program: subtract(31%, 29%)
Answer:
str_answer: 2%
exe_answer: 0.02