There's a very funny construction in the linked article: "... It claims that revenue from paid apps dropped by a drastic -29% in 2013 from the previous year."

There's a very funny construction in the linked article: "... It claims that revenue from paid apps dropped by a drastic -29% in 2013 from the previous year." From a strictly mathematical viewpoint, a drop of -29% is a rise of 29%. You can always identify the math C students later in life.