Costco's worldwide yearly performance along two key metrics is shown in the table below: Year 2014 2015 2016 2017 2018 (Source: Statista) Sales in million U.S. dollars Number of warehouses 110,212 113,666 116,073 126,172 138,434 663 686 715 741 762 Create a new metric, Average Sales per Warehouse, that is a combination of the two metrics, and identify the worst performing year for Costco based on this third metric.