condition mean min max ZT0-3 17.433175 16.083750000000002 18.7826 ZT4-7 12.638000000000002 12.638000000000002 12.638000000000002 ZT8-11 8.693365 8.693365 8.693365 ZT12-15 0 0 0 ZT16-19 14.147 14.147 14.147 ZT20-23 17.5489 17.5489 17.5489