AutoZone and O'Reilly are two competitors in the retail automotive parts industry.

AutoZone O'Reilly
Average 2015 Inventory $3,320,864 $2,632,898
2015 Sales 10,498,448 8,277,782
2015 Cost of goods sold 4,860,30 93,804,031
Average 2014 Inventory $3,040,553 $2,504,914
2014 Sales 9,786,421 7,527,189
2014 Cost of goods sold 4,540,406 3,507,180

Use the information above to compute the companies' gross profit margin and days inventory outstanding for both years.