condition mean min max ZT0-3 4.5083174999999995 4.32823 4.6884049999999995 ZT4-7 2.229335 2.229335 2.229335 ZT8-11 4.632215 4.632215 4.632215 ZT12-15 0 0 0 ZT16-19 11.626925 11.626925 11.626925 ZT20-23 10.69565 10.69565 10.69565