Well, tentatively the top schools are : MIT, Harvard, Caltech, Stanford, Princeton, UCLA etc.

Good luck getting into those schools.

For maintaining cost (and student status while doing your Ph D) in those schools by working in gas stations is a nice joke to tell everyone...

But the good thing is if you get admission in any graduate engineering or natural science programs, they will support you through your tuition and few stipend (enough for survival).

By the way, the percentages you quoted in your Masters/Bachelors donot mean much here.