How to use random forest model in for loop for predicting values for subsequent years, Only have initial year & final year data & rate of change

Question

Using the random forest model, I predict values for a certain period based on two independent variables—initial value and rate of change. • One point to note here: I don’t have data for intermediate years; I have data for only two years, start and end year. • I created a loop to predict values for intermediate years using the build random forest model, but after a specific year, the years in the output file have the same value. and also want to update the initial value in the loop as the previous year of the subsequent year. • I tried visualizing the data and evaluating the model; the residual plot, density plots, and r2 seem fine, but after a particular year, the values are repeating.