condition mean min max ZT0-3 38.045183333333334 25.1369 46.35095 ZT4-7 21.37655 21.37655 21.37655 ZT8-11 19.8778 19.8778 19.8778 ZT12-15 8.521819999999998 6.007949999999999 11.035689999999999 ZT16-19 6.255085 6.255085 6.255085 ZT20-23 18.32615 18.32615 18.32615