condition mean min max ZT0-3 5.86811 5.86811 5.86811 ZT4-7 4.7987850000000005 4.7987850000000005 4.7987850000000005 ZT8-11 9.103485 9.103485 9.103485 ZT12-15 7.989535 7.989535 7.989535 ZT16-19 15.09545 15.09545 15.09545 ZT20-23 7.91187 7.91187 7.91187