    ‘Sentence 1: In:1999:, NIST found , the’ Port.  Authority ‘issued -guidelines...to.upgrade’.the  fireproofing to a thickness of 17/2 inches.    Sentence 2: The NIST discovered that in 1999 thie  Pott Authority issued guidelines to upgrade the  fireproofing to a thickness of 1.1/2 inches .    