condition mean min max ZT0-3 8.043896666666667 6.35271 10.508234999999999 ZT4-7 5.847075 5.847075 5.847075 ZT8-11 7.472535 7.472535 7.472535 ZT12-15 11.102125000000001 9.8289 12.375350000000001 ZT16-19 8.491444999999999 8.491444999999999 8.491444999999999 ZT20-23 8.53148 8.53148 8.53148