Chronology Development scores. Detrending method 1 ¼ RCS (and Signal Free), and 2 ¼ individual detrending. Age range is the difference between highest and lowest point on the mean age curve over the past millennium. Age trend is the slope of a linear regression fit to the mean age curve over the past millennium (times 100). Maximum frequency indicates the wavelength of lowest frequency information retained in a reconstruction, with 1 ¼ centennial to multi-centennial, and 2 ¼ decadal to centennial.