I found this question as weird.
Number of romance is the subject here, it should go with greater than...
amounts shouldn't be there as it is uncountable against number- countable.
amounts goes with larger and number goes with greater.

I would say 'amounted to greater than' sounds better than 'amounted to larger than'. In the sense if we take the opposite of greater, 'amounted to lesser than' would sound better as compared to 'amounted to smaller than', right?
I hope you're getting my point!

With numbers "over" makes more sense than "greater" or "larger". The latter two imply size rather than quantity. You wouldn't say "there were larger/greater than 10 books on the shelf". "There were over ten books on the shelf" is proper. This is very idiomatic!

Tani Wolff - Kaplan wrote:With numbers "over" makes more sense than "greater" or "larger". The latter two imply size rather than quantity. You wouldn't say "there were larger/greater than 10 books on the shelf". "There were over ten books on the shelf" is proper. This is very idiomatic!

Thank you very much, Dear Tani

Can you please explain what differences are between larger and greater?

Thanks in advance

Larger generally refers to physical size where greater refers to quantity. You will, however, find them used interchangeably.

Tani Wolff - Kaplan wrote:Larger generally refers to physical size where greater refers to quantity. You will, however, find them used interchangeably.

Thank you very much.
It helps me as well.

Initially I didn't agree with Tani's explanation.I checked the oxford online dictionary to confirm the usage.I must say she is 100% correct.

great- usage

adjective
1 of an extent, amount, or intensity considerably above average:

the article was of great interest
she showed great potential as an actor

[attributive] used to reinforce another adjective of size or extent:

a great big grin

(also greater)[attributive] used in names of animals or plants which are larger than similar kinds, e.g. great tit, greater celandine.
(Great)[attributive] [in place names] denoting the larger or largest part of a place:

Great Malvern
(Greater)[attributive] (of a city) including adjacent urban areas:
Greater Manchester

2 of ability, quality, or eminence considerably above average:

the great Italian conductor
great art has the power to change lives

[attributive] important or most important:
the great day arrived
the great thing is the challenge

None of these definitions qualifies the usage of great in this sentence.For this reason we say 40 is greater than 30 [the size of 40 relative to 30]

over - usage

preposition

1 extending directly upwards from:

I saw flames over Berlin
cook the sauce over a moderate heat

2 at a higher level or layer than:
his flat was over the shop

3 higher or more than (a specified number or quantity):
over 40 degrees C
they've been married for over a year

This is the meaning used in the sentence at hand.

large -usage

adjective
1 of considerable or relatively great size, extent, or capacity:
add a large clove of garlic
the concert attracted large crowds

This meaning shows the degree of size of an item [single].

A large blue whale
A large number of people. [number is modified by large.It means the number was very big eg 1 million]

2 of wide range or scope:

we can afford to take a larger view of the situation


I think that although these definitions may not be of much help in this question,but they might prove to be very useful in any questions that you might encounter in future.

THank's for the endorsement!