This chart shows the approximate installed base of active Cray Research systems during the 1990s.
The data that shows the XMP (red) being phased out in favour of the YMP (green) and the rise of the smaller J90 and EL systems (orange and yellow) in the later 1990s.
The peek system install base in 1996 being just over 900 systems.
The chart also hints at the longevity of the system types in the customer base. Typically systems being in service for 6..8 years.