condition mean min max ZT0-3 10.439387499999999 9.726725 11.15205 ZT4-7 6.8762799999999995 6.8762799999999995 6.8762799999999995 ZT8-11 7.34277 7.34277 7.34277 ZT12-15 0 0 0 ZT16-19 9.24545 9.24545 9.24545 ZT20-23 10.501475 10.501475 10.501475