condition mean min max ZT0-3 8.032976833333333 0.8863805 12.0196 ZT4-7 1.243335 1.243335 1.243335 ZT8-11 4.67587 4.67587 4.67587 ZT12-15 10.2999525 8.350655 12.24925 ZT16-19 14.9329 14.9329 14.9329 ZT20-23 17.723399999999998 17.723399999999998 17.723399999999998