DuBois, Inc., experienced the following trend in operating profit ratios for the five years ended in 2012.

Operating Income Margin Return on Operating Assets

2012	9.7%	12.2%
2011	9.3%	11.5%
2010	9.1%	11.2%
2009	8.8%	10.6%
2008	8.6%	10.1%

Required:

Using the DuPont analysis, determine whether the trend in turnover increased the return on operating assets or lowered it.