condition mean min max ZT0-3 16.615675 14.1105 19.120849999999997 ZT4-7 11.831299999999999 11.831299999999999 11.831299999999999 ZT8-11 5.338945000000001 5.338945000000001 5.338945000000001 ZT12-15 0 0 0 ZT16-19 7.9795 7.9795 7.9795 ZT20-23 17.2324 17.2324 17.2324