Phrasal verb "accounting for"

Please read:

A/State-owned enterprises led in investment with 1,503 billion USD, accounting for 51/%.

B/The Japanese market accounts for 35% of the company’s revenue.

What is the menaing of account for here?
In (A), why accounting for but not accounted for?


a) account for sth (BE) phrasal verb
to form the total of something:
Students account for the vast majority of our customers.
(Cambridge Advanced Learner’s Dictionary)

b) You can say either ‘accounting for’ or ‘which accounted for’.