condition mean min max ZT0-3 25.449925 22.6914 28.20845 ZT4-7 16.2292 16.2292 16.2292 ZT8-11 4.71242 4.71242 4.71242 ZT12-15 0 0 0 ZT16-19 9.690270000000002 9.690270000000002 9.690270000000002 ZT20-23 16.00835 16.00835 16.00835