I am stuck on this question

Floral Fancy, Ltd. is a retail chain that sells real and fake flowers, flower pots, potting soil, decorative garden items, and other floral accessories. Excerpted portions of three years of its financial statements are below. Income Statement (all numbers in thousands) 2018 2017 2016 Cost of Goods Sold 18957 22454 20310 Balance Sheet (all numbers in thousands) 2018 Inventory 10280 2017 9112 2016 9446 a. Use the information in the tables above to compute days of supply for Floral Fancy's most recent two years. Notes: 1. When calculating the DOS metric, because we're looking at annual data, use 360 days. 2. Computing "average" values requires two time periods of data. For example, to compute 2018 average inventory, we use 2018 inventory as the ending balance, and 2017 inventory as the beginning balance, and average the two numbers. 3. Do not round intermediate calculations. Round your final answer for DOS to a whole number. Metric 2018 2017 Days of supply (DOS) days days b. To indicate improvement in supply chain ROI, DOS should from 2017 to 2018. increase decrease stay the same c. Overall, Floral Fancy's DOS from 2017 to 2018. worsened stayed the same improved