[MINOR] stats: better displaying in MSIE

[MINOR] stats: better displaying in MSIE

MSIE does not correctly display spaced digits. It requires a margin of
at least one pixel. Also, it does not correctly hide empty cells, so we
work around this by setting the background white. Last, the H1 font was
too large, so we reduce it by one size, which is still OK in other
browsers.
(cherry picked from commit da6721ba28d4c917e07ffa7fef1d8707c80c54b6)