Can someone please assist me with understanding the following working capital component of a Capital Budgeting task..

Various experts within Masters have forecast costs and working capital requirements related to the project. Cost of goods sold will equal 50% of sales revenues. Selling, general and administrative expenses directly related to the project (excluding depreciation) will be $1.5 million in the first year and increase by 3% per year thereafter. An upfront investment in net working capital equal to 15% of the year 1 sales revenue forecast will be required. This investment in working capital will be fully recovered at the end year 5.

I have calculated the 15% of working capital (inventory) to be $1,500,000. At waht rate is inventory bought each year? Is it bought? What does it mean for this capital to be fully recovered at the end of year 5?