condition mean min max ZT0-3 7.2958275 6.752605 7.83905 ZT4-7 6.628875 6.628875 6.628875 ZT8-11 8.58389 8.58389 8.58389 ZT12-15 0 0 0 ZT16-19 9.049710000000001 9.049710000000001 9.049710000000001 ZT20-23 8.4816 8.4816 8.4816