Development lead in times from OPP to first dwelling completion - Public forum - Planning Advisory Service (PAS)

Morning all, please does anyone have or can anyone point me in the direction of any published research or information, or your own data that you are prepared to share, about typical times for the above on across the range of development sizes, e.g. sites of 10-50 dwellings, 51-150 dwellings, 150+ dwellings. Ideally, data would be for schemes granted PP since 2011. Any data re: the interim milestones from OPP to first dwelling completion would be welcome too.