condition mean min max ZT0-3 8.798995 8.798995 8.798995 ZT4-7 10.279078 10.279078 10.279078 ZT8-11 11.729068999999999 11.729068999999999 11.729068999999999 ZT12-15 10.190480999999998 10.190480999999998 10.190480999999998 ZT16-19 10.661228000000001 10.661228000000001 10.661228000000001 ZT20-23 10.766322 10.766322 10.766322