hello
maybe this ?
clc
clearvars
realdata=readmatrix('RATM.csv');
Year=realdata(:,1);
realgA=realdata(:,2);
TFPmodel=[0 0.01 0.012 0.015 0.02 0.025 0.025 0.025 0.025 0.025 0.026 0.025 0.026 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025 0.025];
TFPmodel2 = interp1((0:numel(TFPmodel)-1)./numel(TFPmodel),TFPmodel,(0:numel(Year)-1)./numel(Year));
plot(Year, realgA, 'r--', 'LineWidth', 1.5)
hold on
plot(Year,TFPmodel2)
grid on
set(gca,'FontName','Times','FontSize',11);
ylabel('TFP growth (g_A)','FontSize',11)
ylim([-0.01 0.05])
yticks([-0.01 0 0.01 0.02 0.03 0.04 0.05])
xlim([1950 2100])
box on