How long did it take?

It's going to take me the rest of my life.

You obviously do have a calorie deficit, since you are losing weight. Perhaps the others that are losing faster have a larger actual calorie deficit per day? I was going to post that if you go slow with a small deficit, you are practicing maintenance skills and that is a very good thing.

Then I glanced at your diary and saw that you are logging less than 1,200 calories per day with over 1,000 in exercise calories (not eaten back). Has that been true for the whole year? How are you measuring exercise calories? If you are doing that much exercise, you need more than 1,200 calories to sustain it. MFP calculates your deficit already, so you are expected to eat some or all of your exercise calories and you should still lose weight. If you really are netting 200 calories per day you would be starving--literally-- not giving your organs and brain enough to function and losing more than 2 pounds of fat and muscle every week. This leads me to believe that you may be already getting more calories than you think you are, so I'm not suggesting you eat more but instead to verify your numbers.

I would like to suggest three things:

1) that you start weighing (rather than measuring) your food, as well as being sure to log every single thing that you eat or drink (including condiments, etc). Then make sure that the database entries you select are correct by verifying them with another source (such as the USDA).
2) do some research online as to how many calories are burned doing the types of exercise that you do. I don't have a good source for this, but I know people say both exercise machines and MFP overestimate.
3) find a BMR calculator online and determine what yours is. BMR is Basal Metabolic Rate, and is the amount of calories your body burns just being alive, not moving at all (like in a coma). It is what allows your brain and body to do the work of breathing, circulating your blood, repairing tissues, digesting food, etc. An individual who is sedentary still burns approximately 1.2 X their BMR. If you eat less than this amount, consider that you are not giving your body enough fuel to do the most basic work it needs to do to keep you healthy. At 18 years old, even if you are only 5'0" and 139 (since you said you have 39 pounds left to lose), your BMR is around 1332 calories per day. If you are taller or heavier, it is more.

Once you know what you are truly consuming and what you are burning (both by being alive and through exercise), you can pick a calorie deficit level that accomplishes your goals. For the record, I do think a slow, steady loss is easier, but each person is different.

PS, if you've been eating this way for a year and losing weight slowly and steadily, and you feel fine and your doctor is happy, why mess with success? You're doing great. The results speak for themselves, regardless of theories about how people should eat.

Working out 6 days a week could be changing your body fat into muscle so you will have a slower loss. Your doing so well. Everyone is different. Just go at your own pace.