It stands for the 13 national championships they have won
I don't know. What is it for. The 13 games they played
Under the Helmet - 1999 2000-02-12 was released on: USA: 12 February 2000
Under the Helmet - 1999 2000-12-02 was released on: USA: 2 December 2000
Under the Helmet - 1999 2000-12-09 was released on: USA: 9 December 2000
Under the Helmet - 1999 2000-12-16 was released on: USA: 16 December 2000
Under the Helmet - 1999 2000-12-23 was released on: USA: 23 December 2000
Under the Helmet - 1999 2000-12-30 was released on: USA: 30 December 2000
Under the Helmet - 1999 - 1999-12-04 was released on: USA: 4 December 1999
Under the Helmet - 1999 - 1999-12-11 was released on: USA: 11 December 1999
Under the Helmet - 1999 - 1999-12-18 was released on: USA: 18 December 1999
Under the Helmet - 1999 - 1999-12-25 was released on: USA: 25 December 1999