Not a particularly useful figure without knowing which CPU @ what speed.
Assume it is 060@50MHz and this probably is the top figure you'll ever get from an A1200 and that puts the maximum speed at 7Mbit/s.
Here's an excerpt from the original readme:
My network consists of an A1200 603e+/240MHz/060/50MHz connected via
coax cable to a P120 laptop. Software on the Amiga is AmigaOS 3.5 +
Genesis 1.0.6 and on the laptop Debian 2.2. The amiga has Apollo RE450CT
pcmcia card and the laptop has 3com EtherLink III pcmcia card. FTP
download from laptop have reached 786Kbytes/Sec. On overclocked 060
systems speeds of >819Kbytes/Sec have been reported.