condition mean min max ZT0-3 8.782575 8.782575 8.782575 ZT4-7 9.8306595 9.8306595 9.8306595 ZT8-11 8.9836785 8.9836785 8.9836785 ZT12-15 8.782575 8.782575 8.782575 ZT16-19 8.839780999999999 8.839780999999999 8.839780999999999 ZT20-23 7.7774304999999995 7.7774304999999995 7.7774304999999995