Speech readability Speeches by Sabine Lautenschläger, Gunning Fog Index Speech readability yearly average Speeches by Sabine Lautenschläger, Gunning Fog Index: yearly average 15.8 16.3 16.5 14.0 17.0 14.6 16.1 16.6 18.6 15.4 15.4 16.9 18.7 15.6 16.2 17.7 15.3 14.7 14.6 17.3 14.7 16.2 13.9 13.5 15.5 16.3 12.7 13.3 13.2 10.7 11.5 10.6 10.2 10.0 9.4 10.3 10.0 11.0 9.6 10.1 11.8 10.6 10.5 10.6 10.5 9.8 10.0 13.9 10.9 12.6 10.710.6