condition mean min max ZT0-3 8.286592500000001 7.26281 9.310375 ZT4-7 10.675205 10.675205 10.675205 ZT8-11 20.3443 20.3443 20.3443 ZT12-15 0 0 0 ZT16-19 21.4286 21.4286 21.4286 ZT20-23 19.5467 19.5467 19.5467