condition mean min max ZT0-3 279.084433 279.084433 279.084433 ZT4-7 511.362799 511.362799 511.362799 ZT8-11 621.706586 621.706586 621.706586 ZT12-15 379.8200125 379.8200125 379.8200125 ZT16-19 191.66421400000002 191.66421400000002 191.66421400000002 ZT20-23 60.673081499999995 60.673081499999995 60.673081499999995