$1.$ Aircraft turnaround time between flights $2.$ Average age of aircraft in fleet $3.$ Average trip length $($in miles$)4.$ Average wait time when calling reservations center $5.$ Cost per meal served $6.$ Earnings per share $7.$ Employee satisfaction scores $8.$ Employee training programs $9.$ Employee turnover $10.$ Enhancements to product line $($new class of service $)11.$ Load factors $12.$ Market share $13.$ Net income $14.$ New unique features of frequent$-$flier club $15.$ Number of aircraft in fleet $16.$ Number of bags lost $17.$ Number of cities or new cities served $18.$ Number of passenger complaints $19.$ Operating expenses per seat mile $20.$ Passenger revenue per seat mile $21.$ Percentage of on$-$time arrivals