Percentage decrease in the sales of BMW in the year from Q1 to Q4 = (9 – 6)/9 × 100 = 33.33% Percentage increase in the sales of Audi in the year from Q1 to Q4 = (15 – 7)/7 × 100 = 114.28% Percentage decrease in the sales of Jaguar in the year from Q1 to Q4 = (16 – 5)/16 × 100 = 68.75% Percentage decrease in the sales of Porsche in the year from Q1 to Q4 = (12 – 8)/12 × 100 = 33.33% Jaguar faced the maximum decline in the business.