condition mean min max ZT0-3 5.992687500000001 5.03251 6.952865 ZT4-7 6.276325 6.276325 6.276325 ZT8-11 4.56698 4.56698 4.56698 ZT12-15 0 0 0 ZT16-19 8.414655 8.414655 8.414655 ZT20-23 5.9911200000000004 5.9911200000000004 5.9911200000000004