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The Vlasov-Poisson system describes interacting systems of collisionless particles. For solutions with small initial data in three dimensions it is known that the spatial density of particles decays like t^(-3) at late times. In this paper this statement is refined to show that each derivative of the density which is taken leads to an extra power of decay so that in N dimensions for N>2 the derivative of the density of order k decays like t^(-N-k). An asymptotic formula for the solution at late times is also obtained.