Depending on the area you're riding in, you can have an incentive

Incentives are there to make sure you earn more when doing more orders and apply to a payment period (insert link). Incentives depend on the zone you ride in and depend on the average amount of orders in the zone. Earnings are closely monitored and incentives are adapated if necessary.

Check here current incentives

What if you rode in different zones? 
Then only the bonus is applicable from the zone you did the most orders in.