Recruitment by examination flourished after 1384 in the Ming dynasty. Provincial graduates were sometimes appointed to low-ranking offices or entered the Guozijian for further training, after which they might be considered for better appointments. Before appointment to office, metropolitan graduates were assigned to observe the functions of an office for up to one year. The maximum tenure for an office was nine years, but triennial evaluations were also taken, at which point an official could be reassigned. Magistrates of districts submitted monthly evaluation reports to their prefects and the prefects submitted annual evaluations to provincial authorities. Every third year, provincial authorities submitted evaluations to the central government, at which point an "outer evaluation" was conducted, requiring local administration to send representatives to attend a grand audience at the capital. Officials at the capital conducted an evaluation every six years. Capital officials of rank 4 and above were exempted from regular evaluations. Irregular evaluations were conducted by censorial officials.