condition mean min max ZT0-3 10.69431 9.388819999999999 11.9998 ZT4-7 6.72921 6.72921 6.72921 ZT8-11 6.344530000000001 6.344530000000001 6.344530000000001 ZT12-15 0 0 0 ZT16-19 8.629840000000002 8.629840000000002 8.629840000000002 ZT20-23 8.430605 8.430605 8.430605