condition mean min max ZT0-3 8.5328075 8.176459999999999 8.889155 ZT4-7 12.03435 12.03435 12.03435 ZT8-11 10.77675 10.77675 10.77675 ZT12-15 0 0 0 ZT16-19 9.443625 9.443625 9.443625 ZT20-23 10.324295 10.324295 10.324295