As one result in our orbital simulation of the 3372 samples of real NEAs (Near-Earth Asteroids) whose orbits were considered to be well-known, as many as 480 asteroids evolved out of the four major classes (Amor, Apollo, Aten and Atira) of NEAsat the end of the first 500,000 yearsperiodinto Mars-Crossers asteroids in majority. To test the steady statehypothesis for NEAs population, these evolved asteroids had been used as a sample for further simulation to obtain the entrance flux from the Intermediate Sources/IS (in this case the Intermediate Mars-Crossers/IMC only) to NEAs region. The entrance flux from IMC → NEAs region is 71 ± 17 objects per million year for H< 18. Asteroids of this amount as a contribution from IMC (along with contributions from other sources in the Main Asteroid Belt) will be delivered to near-Earth space to replenish this region due to the decay of NEAs population into the Sinks (collide with the Sun/planets or being thrown to the outer Solar System).After5 million years of simulation we found there were 1898 asteroids eliminated from further computational process with the majority endedtheir liveas Sun-grazer and ejected from the Solar System.The near-Earth space lost a total of 114 ± 17 objects per million year for H< 18.The median dynamical lifetime obtained directly from our NEAs sample decay is3.7x106 years.