The Margin-bridge tab explains why your contribution margin changed compared to last year, split into three causes.
A waterfall chart splitting the change into volume, mix and price.
A table of the categories pulling most in each direction.
Read the waterfall from last year to this year: each step shows what explains the change.
Filter by category to zoom in.
Volume: sold more/less. Mix: sold a different mix of products. Price: changed price/margin.