<prompt> In a normal individual, filtration fraction varies from:0.16 - 0.202.0 - 4.00.5 - 0.70.9 - 1.1  <response>: The ratio of the glomerular filtration rate GFR to the renal plasma flow RPF, the filtration fraction, is normally 0.16-0.20. The GFR varies less than the RPF. When there is a fall in systemic blood pressure, the GFR falls less than the RPF because of efferent aeriolar constriction, and consequently the filtration fraction rises. Ref: Barrett K.E., Barman S.M., Boitano S., Brooks H.L. 2012. Chapter 37. Renal Function Micturition. In K.E. Barrett, S.M. Barman, S. Boitano, H.L. Brooks Eds, Ganongs Review of Medical Physiology, 24e. 