condition mean min max ZT0-3 7.591466 7.591466 7.591466 ZT4-7 7.402435499999999 7.402435499999999 7.402435499999999 ZT8-11 8.341361500000001 8.341361500000001 8.341361500000001 ZT12-15 7.623215 7.623215 7.623215 ZT16-19 7.6643159999999995 7.6643159999999995 7.6643159999999995 ZT20-23 7.410434499999999 7.410434499999999 7.410434499999999