In 2008, the number of students studying Arts and commerce together
= (12 + 22)/100 x 35000 = 34 x 350 = 11900
In 2009, the number of students studying Arts and Commerce together
= (11 + 24)/100 x 40000 = 35 x 400 = 14000
Hence, required percentage = 11900/14000 x 100 = 85%