condition mean min max ZT0-3 26.168433333333333 14.89555 33.0469 ZT4-7 7.975415 7.975415 7.975415 ZT8-11 12.248000000000001 12.248000000000001 12.248000000000001 ZT12-15 27.010125 24.15085 29.8694 ZT16-19 30.627850000000002 30.627850000000002 30.627850000000002 ZT20-23 34.82535 34.82535 34.82535