condition mean min max ZT0-3 607.689336 607.689336 607.689336 ZT4-7 715.2704695 715.2704695 715.2704695 ZT8-11 629.807667 629.807667 629.807667 ZT12-15 590.931301 590.931301 590.931301 ZT16-19 388.6170935 388.6170935 388.6170935 ZT20-23 297.662868 297.662868 297.662868