In which year for the company A the percentage increase of production of buses with respect to the previous year is maximum?

Total no. of buses produced by company A in (in '000s) :

2009 = 64

2010 = 70

2011 = 77

2012 = 85

2013 = 93

% increase in 2010 w.r.t previous year = $$\frac{70-64}{64}$$ * 100 = 9.375%

% increase in 2011 w.r.t previous year = $$\frac{77-70}{70}$$ * 100 = 10%

% increase in 2012 w.r.t previous year = $$\frac{85-77}{77}$$ * 100 = 10.38% [MAX]

% increase in 2013 w.r.t previous year = $$\frac{93-85}{85}$$ * 100 = 9.41%

=> % increase in the production of buses by company A was maximum in 2012 with respect to previous year.