U+2007 (Figure Space) should have the same width as a (tabular) figure. One of its use is stand-in for digits in an alignment.
U+2008 (Punctuation Space) should have the same width as a (tabular) comma/period. One of its use is stand-in for thousand separators in a big number.
Also, there seems to be a round error for U+2004 (Three-Per-Em Space).
U+2007 (Figure Space) should have the same width as a (tabular) figure. One of its use is stand-in for digits in an alignment.
U+2008 (Punctuation Space) should have the same width as a (tabular) comma/period. One of its use is stand-in for thousand separators in a big number.
Also, there seems to be a round error for U+2004 (Three-Per-Em Space).