condition mean min max ZT0-3 21.326217 21.326217 21.326217 ZT4-7 21.326217 21.326217 21.326217 ZT8-11 21.82881 21.82881 21.82881 ZT12-15 20.809306999999997 20.809306999999997 20.809306999999997 ZT16-19 21.122261 21.122261 21.122261 ZT20-23 24.3925255 24.3925255 24.3925255