condition mean min max ZT0-3 18.8261 15.1583 22.4939 ZT4-7 9.509045 9.509045 9.509045 ZT8-11 3.50237 3.50237 3.50237 ZT12-15 0 0 0 ZT16-19 3.8194150000000002 3.8194150000000002 3.8194150000000002 ZT20-23 7.49545 7.49545 7.49545