k accuracy seconds 2 0.96270 847.7042 5 0.96880 875.0909 20 0.96250 876.1423 50 0.95340 885.6832 200 0.92890 887.0820 500 0.90390 866.9001 2000 0.82810 874.1006 5000 0.74260 860.8102 0