13 years since we last got either promoted or relegated, that's got to be the longest time in my lifetime. Hopefully we can do back-to-back promotions and reinforce our record of being the club with the most promotions and relegations
EDIT from wiki
Birmingham's longest period in one division has been 18 years in the First Division, from 1921 to 1939. Their next longest is their current stint in the EFL Championship which started in 2011.