Use the field/slider to specify the percentile z used in the Delete rows with Percentile satisfying this expression (use keyword PCTL) filter.A value of 75 % has been specified by default.Note : This field is not active unless an expression has been entered in the Delete rows with Percentile satisfying this expression (use keyword PCTL) filter.Tip : To change the scale of the slider, right-click on the slider and select from the pop-up menu. Change the upper and/or lower boundaries in the window that appears, to rescale the slider and click .