@nemare You're mining with 6.x TB, so can expect to earn around 1 Burst/TB/DAY - so 6 day. Over 6 months, that would be around 1,100 Burst. So you're right on where you should be. You however, also got lucky and were able to mine 5 blocks. So in this case, your have been better off solo mining over that period, however you might not get another block for another 2 years.
You're earning what you should be, but in your case not what you could have over the period, but as I said it could be two more years before you get another one - in which case you'll have still earned the expected average.