condition mean min max ZT0-3 5.6850679985 4.589950963 6.7801850340000005 ZT4-7 5.263230952500001 4.1843429720000005 6.342118933 ZT8-11 8.376991513 6.383894801 10.370088225 ZT12-15 6.92725635575 5.629384382 8.2251283295 ZT16-19 7.7180871415 7.095404242 8.340770041 ZT20-23 10.66518665675 10.258256943500001 11.07211637