TTM20182017201620152014
Gross margin39.8%39.8%39.2%39.0%36.9%37.1%
Gross margin growth (bps)646420211-20-30
Operating margin23.1%23.1%21.8%20.7%18.1%17.2%
Operating margin growth (bps)1351351062609618
Net profit margin15.9%15.9%15.0%14.5%12.7%12.1%
Net profit margin growth (bps)8686511865622