MMI – size of market

Hi

Referring to Q2 MMI https://upload.news.esnai.com/2013/0326/1364283433957.pdf
How do you calculate the size of the market? Because the answer says total revenue fell by 4.5%.

I understand how to calculate the market share. For example in year 20×8, which is to take the revenue 1680 divide by estimated market revenue 6015.
hence: 1680/6015 x 100 = 28% fo YA 20×8

Initially i had taken (6square root (6015/6300) – 1) x100% to asses the growth. But this apparently is wrong. because the period is of 6 years.

Please let me the proper calculation.

Thanks