condition mean min max ZT0-3 468.718708 468.718708 468.718708 ZT4-7 486.510877 486.510877 486.510877 ZT8-11 577.0022015 577.0022015 577.0022015 ZT12-15 563.1610025 563.1610025 563.1610025 ZT16-19 503.33556450000003 503.33556450000003 503.33556450000003 ZT20-23 489.134823 489.134823 489.134823