Number group Earliest known date Front design Designator ------------------------------------------------------------------------------------ 54,000,001 Not seen as yet to 54,100,000 54,100,001 February 2008 Handy Hints T-b1 to T-b4 to and T-a1 to T-a4 54,200,000 54,200,001 February 2008 Handy Hints T-a1 to T-a4 to 54,300,000 54,300,001 February 2008 Handy Hints T-a1 to T-a4 to 54,400,000 54,400,001 February 2008 Handy Hints T-a1 to T-a4 to 54,500,000 54,500,001 February 2008 Handy Hints T-a1 to T-a4 to 54,600,000 54,600,001 February 2008 Handy Hints T-a1 to T-a4 to 54,700,000 54,700,001 Not seen as yet to 54,800,000 54,800,001 Not seen as yet to 54,900,000 54,900,001 February 2008 Handy Hints T-b1 to T-b4 to 55,000,000