9.2 million was calculated as a percentage of 132 million. likewise 13.4 million was determined as a percentage of 142 million. The percent difference between those two percentages was calculated.

I assume you need the difference between the percentages,

if

132 mil ... 100%

9.2 mil ... x

x = (9.2 mil * 100) / 132 = 6.96%

142 mil ... 100%

13.4 mil ... y

y = (13.4 * 100) / 142 = 9.43%

the difference is

9.43-6.96=2.47 %