Hi,
I’m using Ubuntu 15.10 (latest) and it only has libraw10.
$ apt-cache search libraw
libiec61883-0 - an partial implementation of IEC 61883
libiec61883-dev - an partial implementation of IEC 61883
libraw-dev - raw image decoder library (development files)
libraw-doc - raw image decoder library (documentation)
libraw10 - raw image decoder library
libraw1394-11 - library for direct access to IEEE 1394 bus (aka FireWire)
libraw1394-11-dbg - debugging symbols for libraw1394-11
libraw1394-dev - library for direct access to IEEE 1394 bus - development files
libraw1394-doc - Reference manual and documentation about libraw1394
libraw1394-tools - library for direct access to IEEE 1394 bus (aka FireWire)
digikam - digital photo management application for KDE
libkdcraw-data - RAW picture decoding library -- data files
libkdcraw-dev - RAW picture decoding library -- development files
libkdcraw23 - RAW picture decoding library
libkdcraw23-dbg - RAW picture decoding library -- debugging symbols
libraw-bin - raw image decoder library (tools)
librcc-dev - Library for autoconvert codepages development files
darktable - Virtual lighttable and darkroom for photographers