condition mean min max ZT0-3 4.2357466666666665 2.46289 5.914479999999999 ZT4-7 2.69404 2.69404 2.69404 ZT8-11 3.06599 3.06599 3.06599 ZT12-15 5.4189375 4.40754 6.430335 ZT16-19 4.69481 4.69481 4.69481 ZT20-23 6.507875 6.507875 6.507875