Effective lifetime of a mass LLIN distribution, depending on pre-intervention EIR and attrition half-life. Entomological inoculation rate (EIR) is defined as infectious bites per adult per annum (ibpapa). Attrition half-life (years): red lines and crosses = 3, blue lines and crosses = 4, green lines and crosses = 5. Figures c & d EIR: dashed black lines = 2, dashed red lines = 4, dashed green lines = 8, dashed blue lines = 16, light blue lines = 32, magenta lines = 64, yellow lines = 128, grey lines = 256. Figures a & c) Effective lifetime on vertical axis, Figures b & d) Natural logarithm of effective lifetime on vertical axis.