net debt ( 1 ) 3091.3 2970.7 3222.1 cash conversion cycle ( in days ) ( 2 ) 19 19 21 ( 1 ) defined as total debt minus cash and cash equivalents . ( 2 ) cash conversion cycle is defined as days of sales outstanding in accounts receivable and certain receivables due from vendors plus days of supply in merchandise inventory minus days of purchases outstanding in accounts payable and accounts payable-inventory financing , based on a rolling three-month average. .