length      user     system      total        real
before  6      0.010000   0.000000   0.010000 (  0.012378)
after   6      0.010000   0.000000   0.010000 (  0.012866)
before  60     0.040000   0.000000   0.040000 (  0.046273)
after   60     0.040000   0.000000   0.040000 (  0.036421)
before  600    0.390000   0.000000   0.390000 (  0.390670)
after   600    0.210000   0.000000   0.210000 (  0.209094)
before  6000   3.750000   0.000000   3.750000 (  3.751008)
after   6000   1.860000   0.000000   1.860000 (  1.857901)