Why British think 80% of S'poreans coming to UK to study law?

UK Immigration Officer: Purpose of visit?
Visitor: I'm here to study law, sir.
Officer: You know, you must have a lot of lawyers in Singapore .
Visitor: Why do you say that?
Officer: Well, i've been here for a good twenty years, and I'd say 80% of Singaporeans I see here say they're here to read law.
Visitor: Oh, really? That's really something i never knew. Hard to believe in fact.
Officer: Just you watch, then. You just stand here until the next Singaporean comes along, and I'll bet he's here to read law.
*Visitor waits for 5 mins, Ah Chong from Singapore comes to immigrationcounter*
Officer: Mr. Ah Chong, purpose of visit?
Ah Chong: Study lorr...