2016...not yet.
The coolant shouldn't go anywhere. There can be a very small amount of evaporation, but it's an almost sealed system.
Close to the low mark is OK when the coolant is cold--mine is 1/2" above the L mark, and it's been there a long time. If you add too much, when it heats and expands it'll expel the excess. When you refill it, how high did you go? The F line on the plastic reservoir is the most it should be when cold. Check the level when it is hot and when it is cold. Note that the coolant in the radiator varies in temperature depending on the warmth of the day and the load you're putting on the engine. On a hot day when you're driving hard it could be at or above the F line but not at the top of the plastic chamber.
If you are only filling to the F line, and the cold level drops below the L line, you need to have the leak found & fixed.
The coolant is Mazda FL22, a pre-diluted product. Apparently there is an identical Ford coolant at a better price, VC-10-A for the pre-diluted and VC-10-A2 for the concentrated product which needs to be diluted 50/50 with distilled water. Ravenol J4D2092 seems to be an identical product. Coolants have become very complex due to the combinations of metals used in the different manufacturer's engines. There are some all-purpose coolants that are probably suitable in our engines, but I would only use those after a complete drain & flush.
