condition mean min max ZT0-3 7.45476 6.527075 8.382445 ZT4-7 6.63047 6.63047 6.63047 ZT8-11 9.058910000000001 9.058910000000001 9.058910000000001 ZT12-15 0 0 0 ZT16-19 8.039805000000001 8.039805000000001 8.039805000000001 ZT20-23 7.16312 7.16312 7.16312