condition mean min max ZT0-3 6.5865675 6.54108 6.632055 ZT4-7 5.050789999999999 5.050789999999999 5.050789999999999 ZT8-11 4.059965 4.059965 4.059965 ZT12-15 0 0 0 ZT16-19 6.617414999999999 6.617414999999999 6.617414999999999 ZT20-23 7.752879999999999 7.752879999999999 7.752879999999999