condition mean min max ZT0-3 10.11798 10.11798 10.11798 ZT4-7 8.23951 8.23951 8.23951 ZT8-11 7.906655 7.906655 7.906655 ZT12-15 8.377455 8.377455 8.377455 ZT16-19 9.594745 9.594745 9.594745 ZT20-23 8.56276 8.56276 8.56276