I've already identified the code in question, but it's a little more complicated.

Furthermore there is also the "remaining" part, and the search could go backwards.

Interested pmdevs can submit patches here

 511:           . qq[ (searched ] . sprintf( "%.2f",
 512:               100*( abs($n0-$start)+1 ) / $lastNode
 513:             ) . qq[% of DB).</div><br />\n<div class="ss-criteri
+a-summary">\n];
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and

 569:         } else {
 570:             my( $min, $max )= $oldFirst ? ( $n0, $lastNode ) : (
+ 1, $n0 );
 571:             my $pct= sprintf "%.2f%%", 100*($max-$min+1)/$lastNo
+de;
 572:             if(  1 == $doSearch  ) {
 573:                 $html .= qq[Press ]
 574:                   . $q->submit( "nx", "Next >" )
 575:                   . qq[ to <b>continue</b> searching remaining $
+pct of DB.];
 576:             } else {
[download]