condition mean min max ZT0-3 22.038025 20.0991 23.976950000000002 ZT4-7 23.08775 23.08775 23.08775 ZT8-11 18.135150000000003 18.135150000000003 18.135150000000003 ZT12-15 0 0 0 ZT16-19 17.13455 17.13455 17.13455 ZT20-23 22.2623 22.2623 22.2623