Q2 2018Q1 2018Q4 2017Q3 2017Q2 2017
Gross margin28.5%31.8%27.2%33.8%28.4%
Gross margin growth (bps)2-265245-301-509
Operating margin-8.4%-6.1%-10.5%-1.6%-9.0%
Operating margin growth (bps)64-2001,026-496-484
Net profit margin-8.5%-6.2%-9.6%-1.6%-9.1%
Net profit margin growth (bps)61-2031,070-492-479

Notes:The company changed its fiscal year in 2011 from the end of February to the end of January; therefore, fiscal 2011 only includes 48 weeks of operations and Q4 2011 only includes 9 weeks of operations