condition mean min max ZT0-3 9.901745 9.901745 9.901745 ZT4-7 10.90075 10.90075 10.90075 ZT8-11 7.357094999999999 7.357094999999999 7.357094999999999 ZT12-15 5.750954999999999 5.750954999999999 5.750954999999999 ZT16-19 8.321995 8.321995 8.321995 ZT20-23 11.90405 11.90405 11.90405