How does the 1991-2006 refurbishment relate to the 1999-2007 imply edit

The text implies two overlapping periods of work on the tunnel. One started in 1991 and finished in 2006. The other starting after the Mont Blanc tunnel fire in 1999 and finishing in 2007. Are these different are the same?. Really need cites to determine. -- chris_j_wood (talk) 13:26, 21 July 2014 (UTC)Reply