I don't know the formula for average life of assets and asset turnover. Could you please tell me the formula for those two?

Panera Chipotle 2015 2014 2015 2014 Average life of assets 14.87 15.58 Average age of assets 5.36 5.51 5.53 5.55 Asset turnover The average life and age of assets have been consistent from year to year. The average age of the 4. What is the estimated life of Chipotle's and Panera Bread's assets? If the asset is not included in the c Assets Chipotle Panera Bread