Apoptosis
The average adult human loses between 50 and 70 billion cells each day due to apoptosis. The average human adult has more than 13 trillion cells  of which at most only 70 billion die each day. That is, about 5 out of every 1,000 cells (0.5%) die each day due to apoptosis. For an average human child between the ages of 8 and 14, approximately 20–30 billion cells die per day.