White-collar workers grew rapidly as blue-collar share fell below half by 1925.

Evidence

The facts behind research in this area were that the number of white-collar workers had increased rapidly as a proportion of those in employment, and that the proportion of blue-collar workers, which in 1925 was already less than 50 per cent, was decreasing, even in areas such as heavy industry and mining, where manual workers were still the great majority. — Rolf Wiggershaus, The Frankfurt School, 465

Categorization

• corroborated: 2 independent passages support this claim — Rolf Wiggershaus, The Frankfurt School: Its History,…, 465
• XREF: connects to: Blue-collar workers were already under half the workforce by 1925 and shrinking further — Rolf Wiggershaus, The Frankfurt School: Its History,…, 465