Scatter plot for freeze-in temperatures of two selected populations in four types, details have been marked in the legend. C_β(p_c1,p_c2) means the horizontal coordinate is the temperature of C_β-p_c1, while the vertical coordinate is the temperature of C_β-p_c2. The error bar for Case No. 96 estimated from Test. 3 is marked as well, together with the error bar for Case No. 179. (a) Scatter plot for freeze-in temperatures of Type C_α and Type H_α. (b) Scatter plot for freeze-in temperatures of two neighboring populations of Type C_α and Type H_α. (c) Scatter plot for freeze-in temperatures of two neighboring populations of Type C_α and Type H_α. (d) Scatter plot for freeze-in temperatures of hot populations and their neighboring populations of Type H_α and Type H_β.