for 𝜁 = 𝑇 * , 𝑇 1 and 𝑋, respectively. This fitting function is interesting because it has the theoretical properties 𝑃 ? and 𝑃 M of Appendix C. Furthermore, as 𝑘 9CD 0? increases, RMSE j;E <=> exhibits compatible behavior. This is the case except for 𝑘 9CD < 10 M , as will be seen below.