condition mean min max ZT0-3 9.936965 8.77298 11.100950000000001 ZT4-7 6.13198 6.13198 6.13198 ZT8-11 4.148435 4.148435 4.148435 ZT12-15 0 0 0 ZT16-19 7.142405 7.142405 7.142405 ZT20-23 8.030535 8.030535 8.030535