condition mean min max ZT0-3 7.588022499999999 7.405575 7.7704699999999995 ZT4-7 6.875605 6.875605 6.875605 ZT8-11 8.08022 8.08022 8.08022 ZT12-15 0 0 0 ZT16-19 7.4752849999999995 7.4752849999999995 7.4752849999999995 ZT20-23 9.35691 9.35691 9.35691