sparkline.org no longer hosts the php sparkline software. it redirects to a personal website which points people at github for their projects, and that list does not include sparkline.
php5 is no longer available in Debian stable (or oldstable).
the libphp-sparkline package is broken with php7 CLI (it redefines "Object" which is now reserved).
Perhaps reverting to the Perl sparkline would make sense now? — Jon
oh, now I see remove orphaned sparkline-php from Suggests.