It looks like you have 2 flights that depart within 10 minutes of each other. In the system, if the flights are scheduled too close together they are counted as basically the same flight and will split the passengers that would've gone on the one flight. Other than that I would say check to see what your route image is. It takes awhile to grow that route image without marketing (Not that route marketing would necessarily be beneficial).
Patience is the name of the game currently. Each airline is still figuring out what is working and what isn't.
EDIT: I just checked your flights again. In addition to the two flights within 10 minutes of each other, you have an additional 2 flights leaving at the exact same time. Same rule applies, so to fix it, I would just space the departure times out (Ideally, at least an hour between each flight)