condition mean min max ZT0-3 6.18269 6.18269 6.18269 ZT4-7 7.449975 7.449975 7.449975 ZT8-11 6.083925000000001 6.083925000000001 6.083925000000001 ZT12-15 5.025729999999999 5.025729999999999 5.025729999999999 ZT16-19 5.91088 5.91088 5.91088 ZT20-23 2.81484 2.81484 2.81484