condition mean min max ZT0-3 0.139047159 0.0 0.278094318 ZT4-7 2.22225316125 1.702410518 2.7420958045 ZT8-11 5.036444552499999 4.067081934 6.005807170999999 ZT12-15 7.58394494275 7.1695165759999995 7.9983733095 ZT16-19 8.2050018295 7.104883857 9.305119802 ZT20-23 10.469027897 8.958390263999998 11.97966553