condition mean min max ZT0-3 9.519207 9.519207 9.519207 ZT4-7 10.022609500000002 10.022609500000002 10.022609500000002 ZT8-11 9.7606975 9.7606975 9.7606975 ZT12-15 8.638382 8.638382 8.638382 ZT16-19 9.275780999999998 9.275780999999998 9.275780999999998 ZT20-23 9.5993025 9.5993025 9.5993025