condition mean min max ZT0-3 17.98845 17.98845 17.98845 ZT4-7 11.6324 11.6324 11.6324 ZT8-11 12.00045 12.00045 12.00045 ZT12-15 13.1691 13.1691 13.1691 ZT16-19 17.19725 17.19725 17.19725 ZT20-23 20.94795 20.94795 20.94795