Raw speed is the crucial component in producing certain time, at least in 200m indeed.
An easy way to find the average speed in km/h is to divide 200 by 9.75 and multiple by 3.6.
Alternatively, some communiques provide the speed and the Keirin finals communiquee stated winning speeds of over 73 kmh.
Keirin finals communique. Probably all communiques are headed as Asian Track Championships Korea 2019 but "2019" is obviously by mistake.