It is a tricky question. There is no specific answer to this question rather there are few questions that you should ask yourself to MEASURE how mature your team is with respect to the Scrum process.

• Is your team self-organized?
• Is your customer satisfied with your deliveries?
• How MANY FIELD issues after installation of the software?
• Is the software delivered on time?
• What kind of behavioural improvement is seen after applying scrum process?
• Are people transparent and sharing their feedback openly?
• Are people ready to take feedback from the customers and ready for any continuous improvement?
• Is the cycle time IMPROVING as you progress in scrum?
• Do you have a predictable delivery or velocity?
• How did the scrum affect the speed of the delivery?
• What kind of outcomes you are able to predict because of Scrum?

It is not COMPULSORY to measure each and every point but the interviewer is expecting you to give him a few examples to measure. The customer value and speed of delivery are the two pillars of maturity in your process.