Figure 5. Relationship between the average length increment from age one to four years (mm·1-4 years-1) for the different cohorts of perch and a) summer water temperature (three-year moving-average, SMA), b) relative density (three-year moving-average, CPUE) with solid lines representing the multiple linear regression model results (predictors centred and scaled). c) The relationship between age at maturation (A50, given by logistic regression) and average length increment from age one to four years for the different perch cohorts from 1998-2013, with the solid line representing the linear regression model and shaded area depicting the standard error of the model. NB. Lakes were pooled in the linear regressions because no significant difference in the slope between lakes were detected.