condition mean min max ZT0-3 4.311823333333333 3.86659 4.549595 ZT4-7 4.718765 4.718765 4.718765 ZT8-11 3.50406 3.50406 3.50406 ZT12-15 5.8401975 5.384275000000001 6.29612 ZT16-19 3.96782 3.96782 3.96782 ZT20-23 4.701874999999999 4.701874999999999 4.701874999999999