condition mean min max ZT0-3 7.4598025 6.96513 7.954475 ZT4-7 8.514520000000001 8.514520000000001 8.514520000000001 ZT8-11 6.4072499999999994 6.4072499999999994 6.4072499999999994 ZT12-15 0 0 0 ZT16-19 10.30019 10.30019 10.30019 ZT20-23 11.89615 11.89615 11.89615