condition mean min max ZT0-3 11.677 11.677 11.677 ZT4-7 6.71168 6.71168 6.71168 ZT8-11 7.555925 7.555925 7.555925 ZT12-15 6.653725 6.653725 6.653725 ZT16-19 13.2119 13.2119 13.2119 ZT20-23 13.90145 13.90145 13.90145