A circular disc of radius R carries surface charge density σ(r) = σ₀(1 − r/R), where σ₀ is a constant and r is the distance from the center of the disc. Electric flux through a large spherical surface that encloses the charged disc completely is ϕ₀. Electric flux through another spherical surface of radius R/4 and concentric with the disc is ϕ. Then the ratio ϕ₀/ϕ is _____.