condition mean min max ZT0-3 1.6266835 1.1637605 1.9770050000000001 ZT4-7 1.001369 1.001369 1.001369 ZT8-11 1.1616374999999999 1.1616374999999999 1.1616374999999999 ZT12-15 3.45688 3.020495 3.893265 ZT16-19 2.69265 2.69265 2.69265 ZT20-23 2.342535 2.342535 2.342535