condition mean min max ZT0-3 10.586879 10.586879 10.586879 ZT4-7 9.6637365 9.6637365 9.6637365 ZT8-11 10.1146785 10.1146785 10.1146785 ZT12-15 8.386237 8.386237 8.386237 ZT16-19 8.8039895 8.8039895 8.8039895 ZT20-23 8.5205285 8.5205285 8.5205285