condition mean min max ZT0-3 8.3968775 8.058645 8.73511 ZT4-7 9.549225 9.549225 9.549225 ZT8-11 10.351935 10.351935 10.351935 ZT12-15 0 0 0 ZT16-19 10.4097 10.4097 10.4097 ZT20-23 11.10795 11.10795 11.10795