condition mean min max ZT0-3 23.338973 23.338973 23.338973 ZT4-7 31.627015999999998 31.627015999999998 31.627015999999998 ZT8-11 47.9191355 47.9191355 47.9191355 ZT12-15 58.921863 58.921863 58.921863 ZT16-19 53.255343999999994 53.255343999999994 53.255343999999994 ZT20-23 36.008388 36.008388 36.008388