How to handle friend zone?

So I knew this girl since freshmen of college, and now we're juniors.

Problem is. we meet every semester, cuz I ask her if she wants to meet, and she always answers 10 to 20 minutes later. But the catch is after the meeting, she responds 24 hours later. Then, when when next season comes, she responds quickly again.

And I pay for the meal. What's going on?
Should I make it clear that I like her?

?2015-06-05T03:51:53Z

Stop using the word "friend zone"

Guys and girls can be friends and a fact of life is most people are not interested in most people. Women go for people they have something in common with and they are attracted to, if she's a bombshell that dates abusive guys with rap albums and that call her a b*tch all the time and keeps getting hurt but refuses to date the average Joe, let her, she has something in common with them and is interested in them for a reason.

If she sees you as a friend only then just let it be, be friends and move on.

?2015-06-05T03:51:30Z

I'm not American, so I'm not familiar with your schooling terms or how long you've been speaking to each other.
If you are leaving it a long time between contacting her and hanging out, she may well assume that YOU'VE friendzoned HER.
On the other hand, she could just be using you for a free meal every now and then.
You need to be upfront with her about how you feel and what you want.