Difference in the output of lsim()/impulse() between Octave

clear
close all hidden

t = (0 : 0.1 : 10).';
u = [2.0863, 2.0203, 1.9321, 1.8324, 1.728, 1.6231, 1.5205, 1.4217, 1.3275, ...
     1.2384, 1.1545, 1.0758, 1.0022, 0.93332, 0.86907, 0.80915, 0.75329, ...
     0.70126, 0.65279, 0.60765, 0.56562, 0.52649, 0.49007, 0.45616, 0.42459, ...
     0.39521, 0.36786, 0.3424, 0.3187, 0.29664, 0.27611, 0.257, 0.23921, ...
     0.22265, 0.20724, 0.1929, 0.17955, 0.16712, 0.15555, 0.14478, 0.13476, ...
     0.12543, 0.11675, 0.10866, 0.10114, 0.094138, 0.08762, 0.081552, ...
     0.075904, 0.070647, 0.065753, 0.061198, 0.056957, 0.05301, 0.049335, ...
     0.045915, 0.04273, 0.039766, 0.037006, 0.034437, 0.032045, 0.029817, ...
     0.027744, 0.025813, 0.024014, 0.02234, 0.02078, 0.019327, 0.017974, ...
     0.016713, 0.015539, 0.014444, 0.013424, 0.012472, 0.011585, 0.010758, ...
     0.0099854, 0.0092646, 0.0085915, 0.0079626, 0.0073746, 0.0068246, ...
     0.0063097, 0.0058271, 0.0053745, 0.0049493, 0.0045494, 0.0041726, ...
     0.0038168, 0.0034799, 0.0031597, 0.0028539, 0.0025603, 0.0022757, ...
     0.0019967, 0.0017186, 0.0014351, 0.0011375, 0.00081301, 0.00044306, 0].';

sys = ss([0, 1; 2, -3], [0;  1], [1, 0; 0, 1], [0; 0]);

y_imp = impulse(sys, t(end));
[y_sim, t_sim] = lsim(sys, u, t, [-0.8; 1].');

fprintf('Final value of impulse = (%f/%f)\n', y_imp(end, 1), y_imp(end, 2));
fprintf('Final value of simulation = (%f/%f)\n', y_sim(end, 1), y_sim(end, 2));

plot(t_sim, y_sim);