This page narrows Glyph down to Death Knight only, so the table stays scoped to one subtype instead of the full category list.
Death Knight listings clear and replenish at whatever pace the in-game market sets; some subtypes trade in volume, others sit static for stretches. The price-history chart on each row's detail page makes that pattern visible at a glance.
Sort the table by item level or required level to find what matters for your character, or click through to any row for its full price-history chart across realms and game versions.