  The great development of astrometric accuracy since the observations by
Hipparchus about 150 BC was documented in 2008 in the first version of the
present report. This report was updated in H{\o}g (2017d), e.g. with recent
information on the catalogues before 1800 AD. The development has often been
displayed in diagrams showing the accuracy versus time. A new simplified
diagram is provided in the present report as Fig.2 and in a .png file and this
information will presumably be the main interest for some readers.
