Q4 2018Q3 2018Q2 2018Q1 2018Q4 2017
Gross margin38.3%38.3%38.3%38.4%37.9%
Gross margin growth (bps)38-17-62-11-11
Operating margin25.6%23.7%26.0%29.8%25.0%
Operating margin growth (bps)67-4-65-6-15
Net profit margin22.5%21.6%22.6%22.7%20.4%
Net profit margin growth (bps)208243176-11114