gettext uses a heuristic to guess whether a translatable string is a printf
format string. In this case, it guesses wrong, so add a comment that tells
gettext that "% of Variance" is not a format string.
Without this change, the translationproject.org robot rejects translations.
Reported by fxmiguel@gmail.com.
for (i = 0; i < (nc - heading_columns) / 3 ; ++i)
{
tab_text (t, i * 3 + 1, 1, TAB_CENTER | TAT_TITLE, _("Total"));
+ /* xgettext:no-c-format */
tab_text (t, i * 3 + 2, 1, TAB_CENTER | TAT_TITLE, _("% of Variance"));
tab_text (t, i * 3 + 3, 1, TAB_CENTER | TAT_TITLE, _("Cumulative %"));