/usr/ is in libplotmm-dev 0.1.2-2.
This file is owned by root:root, with mode 0o755.
..
/usr/share/
/usr/share/doc/
/usr/share/doc/libplotmm-dev/
/usr/share/doc/libplotmm-dev/copyright
/usr/include/
/usr/include/plotmm/
/usr/include/plotmm/scale.h
/usr/include/plotmm/doublerect.h
/usr/include/plotmm/scalediv.h
/usr/include/plotmm/paint.h
/usr/include/plotmm/symbol.h
/usr/include/plotmm/compat.h
/usr/include/plotmm/doubleintmap.h
/usr/include/plotmm/rectangle.h
/usr/include/plotmm/supplemental.h
/usr/include/plotmm/curve.h
/usr/include/plotmm/plot.h
/usr/include/plotmm/errorcurve.h
/usr/lib/
/usr/lib/x86_64-linux-gnu/
/usr/lib/x86_64-linux-gnu/pkgconfig/
/usr/lib/x86_64-linux-gnu/pkgconfig/plotmm.pc
/usr/share/doc/libplotmm-dev/changelog.Debian.gz
/usr/lib/x86_64-linux-gnu/libplotmm.so