Should you write in plural form rather than singular?

Selected data for stick’s design are given as of december 31, year 1 and year 2 (rounded to the nearest hundredth). year 2 year 1 net credit sales $25,000 $30,000 cost of goods sold 16,000 18,000 net income 2,000 2,800 cash 5,000 900 accounts receivable 3,000 2,000 inventory 2,000 3,600 current liabilities 6,000 5,000 compute the following: 1. current ratio for year 2 2. acid-test ratio for year 2 3. accounts receivable turnover for year 2 4. average collection period for year 2 5. inventory turnover for year 2