Financial report context:
fiscal 2011 , primarily because of increased business levels , an increase in revenue related to the sale and lease of our hardware products and increased revenue recognized from bookings in prior periods . maintenance revenue decreased on a standalone basis during fiscal 2012 as compared to fiscal 2011 , primarily because of the increased allocation to product revenue due to the gradual decline in the average duration of our time-based software license arrangements over the last three years . product and maintenance revenue increased during fiscal 2011 , as compared to fiscal 2010 , due to reasons noted above and also due to the increase in revenue from the denali business which we acquired in the second quarter of 2010 . we expect the aggregate of product and maintenance revenue will increase during fiscal 2013 due to increases in the revenue from our software and ip products , partially offset by an expected decrease in revenue from our hardware products . services revenue decreased during fiscal 2012 , as compared to fiscal 2011 , primarily because certain of our design services engineers have been redeployed to internal research and development projects and to assist with pre-sales activities . services revenue increased during fiscal 2011 , as compared to fiscal 2010 , primarily because of cash collections from customers on orders fulfilled in years prior to 2011 for which revenue was recognized in fiscal 2011 upon receipt of cash payment , and because of higher utilization rates for our services personnel . we expect services revenue to decrease during fiscal 2013 , as compared to fiscal 2012 , as we expect certain of our design services engineers will continue to work on internal research and development projects , primarily related or our design ip and vip activities . revenue by product group the following table shows the percentage of product and related maintenance revenue contributed by each of our five product groups , and services and other during fiscal 2012 , 2011 and 2010: .

Financial table:
2012: functional verification hardware and ip; 2011: 30% ( 30 % ); 2010: 30% ( 30 % ); column_4: 24% ( 24 % )
2012: custom ic design; 2011: 23% ( 23 % ); 2010: 22% ( 22 % ); column_4: 26% ( 26 % )
2012: digital ic design; 2011: 23% ( 23 % ); 2010: 22% ( 22 % ); column_4: 23% ( 23 % )
2012: system interconnect design; 2011: 9% ( 9 % ); 2010: 9% ( 9 % ); column_4: 9% ( 9 % )
2012: design for manufacturing; 2011: 6% ( 6 % ); 2010: 7% ( 7 % ); column_4: 7% ( 7 % )
2012: services and other; 2011: 9% ( 9 % ); 2010: 10% ( 10 % ); column_4: 11% ( 11 % )
2012: total; 2011: 100% ( 100 % ); 2010: 100% ( 100 % ); column_4: 100% ( 100 % )

Additional report context:
as described in note 2 in the notes to consolidated financial statements , certain of our licensing arrangements allow customers the ability to remix among software products . additionally , we have arrangements with customers that include a combination of our products , with the actual product selection and number of licensed users to be determined at a later date . for these arrangements , we estimate the allocation of the revenue to product groups based upon the expected usage of our products . the actual usage of our products by these customers may differ and , if that proves to be the case , the revenue allocation in the table above would differ . the changes in the percentage of revenue contributed by the functional verification , hardware and ip product group are generally related to changes in revenue related to our hardware products. .

Question: what is the difference in the percentage of product and related maintenance revenue contributed by the custom ic design product group in 2010 versus 2012?
Answer: -3%