condition mean min max ZT0-3 10.2134575 8.911725 11.51519 ZT4-7 15.78665 15.78665 15.78665 ZT8-11 6.799384999999999 6.799384999999999 6.799384999999999 ZT12-15 0 0 0 ZT16-19 13.62506 13.62506 13.62506 ZT20-23 17.1192 17.1192 17.1192