That obviously depends on the field size. In a 9-max 18-man SnG an average player will make the final table 50% of the time and a solid winner maybe 52-55% of the time. In a 9-man 900 player MTT an average player will make the final table 1% of the time and a solid winner maybe 1,2-1,3% of the time. So if you mainly play large field MTTs with 1.000 or more participants, then this is, what you signed up for. Final table appearances are going to be rare, and as a result of this downswings can be huge and last for 1.000`th of tournaments.