condition mean min max ZT0-3 9.310478 9.310478 9.310478 ZT4-7 17.3005025 17.3005025 17.3005025 ZT8-11 18.110063 18.110063 18.110063 ZT12-15 15.2515605 15.2515605 15.2515605 ZT16-19 12.944118499999998 12.944118499999998 12.944118499999998 ZT20-23 12.358836 12.358836 12.358836