Here is some information regarding capacity, which is correct in detail
Freehold purchase and conversion to all seater
The club purchased the freehold of the ground from Plymouth City Council to become sole owners in December 2006 for £2.7m. It was hoped that work on a new Grandstand would begin the following year. It hosted its biggest crowd since the redevelopment in March 2007 when 20,652 were in attendance to watch Argyle play Watford in the quarter-finals of the FA Cup. That summer the ground became all-seated as the club was forced to convert the Mayflower Terrace into seating by the Department for Culture, Media and Sport. In the aftermath of the Hillsborough disaster in 1989 regulations were brought in, recommended by the Taylor report, that all stadiums in the top two divisions of English football must be all-seated unless there are exceptional circumstances. The club had been given three years grace after winning promotion back to the Football League Championship in 2004.
Three major summer initiatives were announced by the club just over a week later, which were carried out over the next month. The Mayflower Terrace was replaced by temporary, unreserved seating with a capacity of 3,500. A new state-of-the-art public address system was installed, and the last of ground's inconic floodlight towers were dismantled after 54 years of service, with a new system put in its place. The capacity of the ground was therefore reduced by roughly two thousand to 19,500 following these changes.