condition mean min max ZT0-3 10.321882999 8.799233512 11.844532486 ZT4-7 18.9452380775 17.046043415 20.844432740000002 ZT8-11 22.399817669999997 18.80889267 25.99074267 ZT12-15 37.7615064725 36.747489225 38.775523719999995 ZT16-19 38.696846895 38.046703074999996 39.346990715000004 ZT20-23 45.82003922 43.84100567 47.799072769999995