What is b₀? (Keep two decimal places)

Arms Kick Time (min) 600 1,700 55.2 300 900 22.1 300 1,700 39.2 400 1,900 45.2 450 1,400 43.6 300 800 21.8 300 1,400 34.3 300 1,400 34.4 250 1,800 42.2 300 2,300 56.1 400 2,200 54.2 500 1,700 46.8 200 1,100 26.4 300 1,600 39.3 150 1,900 39.8 200 2,200 45.7 400 1,500 40.1 300 1,800 42.0 200 900 21.3 150 900 20.0 300 1,400 39.5 500 1,400 45.1 600 1,400 47.7 400 1,700 46.8 400 2,000 54.9