condition mean min max ZT0-3 10.724424 10.724424 10.724424 ZT4-7 10.385283000000001 10.385283000000001 10.385283000000001 ZT8-11 8.359102 8.359102 8.359102 ZT12-15 7.786441999999999 7.786441999999999 7.786441999999999 ZT16-19 8.310862 8.310862 8.310862 ZT20-23 8.541359 8.541359 8.541359