Spotted...

This data is three years old, Oliver. I am disappoint.

What Ed said. 5'5" isn't short, it's above average height. Here's a table, which may or may not be a good collection of estimates, but it seems credible:

Men:
U.K. – England 1.776 m (5 ft 10 in) 25–34 Measured 2008
U.K. – England 1.753 m (5 ft 9 in) Adults Measured 2008
U.K. – Scotland 1.782 m (5 ft 10 in) 25–34 Measured 2008
U.K. – Scotland 1.750 m (5 ft 9 in) Adults Measured 2008
U.K. – Wales 1.770 m (5 ft 9 1⁄2 in) Adults Measured 2009

Women:
U.K. – England 1.637 m (5 ft 4 1⁄2 in) 25–34 Measured 2008
U.K. – England 1.616 m (5 ft 3 1⁄2 in) Adults Measured 2008
U.K. – Scotland 1.635 m (5 ft 4 1⁄2 in) 25–34 Measured 2008
U.K. – Scotland 1.613 m (5 ft 3 1⁄2 in) Adults Measured 2008
U.K. – Wales 1.620 m (5 ft 4 in) Adults Measured 2009