condition mean min max ZT0-3 9.012975 9.012975 9.012975 ZT4-7 5.12179 5.12179 5.12179 ZT8-11 5.502835 5.502835 5.502835 ZT12-15 6.193975 6.193975 6.193975 ZT16-19 11.113150000000001 11.113150000000001 11.113150000000001 ZT20-23 9.13533 9.13533 9.13533