That is the magic of dynamic fare policy. Booking percentage of Patna Rajdhani is the least, but still it managed to earn more than Rs. 60 crores. Usually Patna Rajdhani runs with 100% occupancy and tops the list in terms of earnings. Also Patna Rajdhani is the only train in the list whose % Earning is higher than % Booking.
Booking percentage of a train covering large distance with plenty of intermediate booking, will always be high.