condition mean min max ZT0-3 7.761002613 7.007878836 8.51412639 ZT4-7 5.41667922375 4.5141441005 6.319214346999999 ZT8-11 6.30108982825 5.761529354 6.8406503025 ZT12-15 8.62716747325 7.0297954455 10.224539500999999 ZT16-19 11.5940894805 10.31287715 12.875301811 ZT20-23 19.653146042499998 17.216492665 22.08979942