condition mean min max ZT0-3 7.066612500000001 6.411355 7.721870000000001 ZT4-7 3.544325 3.544325 3.544325 ZT8-11 5.023265 5.023265 5.023265 ZT12-15 0 0 0 ZT16-19 5.97459 5.97459 5.97459 ZT20-23 6.29241 6.29241 6.29241