condition mean min max ZT0-3 7.93578 7.573195 8.298365 ZT4-7 10.7777 10.7777 10.7777 ZT8-11 8.803335 8.803335 8.803335 ZT12-15 0 0 0 ZT16-19 9.145465000000002 9.145465000000002 9.145465000000002 ZT20-23 11.80125 11.80125 11.80125