SELECT DunsNumber, ( Emp91 - Emp90 ) / ( 0.5 * ( Emp91 + Emp90 ) ) as delEmp1991,  ( Emp92 - Emp91 ) / ( 0.5 * ( Emp92 + Emp91 ) ) as delEmp1992,  ( Emp93 - Emp92 ) / ( 0.5 * ( Emp93 + Emp92 ) ) as delEmp1993,  ( Emp94 - Emp93 ) / ( 0.5 * ( Emp94 + Emp93 ) ) as delEmp1994,  ( Emp95 - Emp94 ) / ( 0.5 * ( Emp95 + Emp94 ) ) as delEmp1995,  ( Emp96 - Emp95 ) / ( 0.5 * ( Emp96 + Emp95 ) ) as delEmp1996,  ( Emp97 - Emp96 ) / ( 0.5 * ( Emp97 + Emp96 ) ) as delEmp1997,  ( Emp98 - Emp97 ) / ( 0.5 * ( Emp98 + Emp97 ) ) as delEmp1998,  ( Emp99 - Emp98 ) / ( 0.5 * ( Emp99 + Emp98 ) ) as delEmp1999, Emp00 - Emp99 / 0.5 * ( Emp00 + Emp99 ) as delEmp2000,  ( Emp01 - Emp00 ) / ( 0.5 * ( Emp01 + Emp00 ) ) as delEmp2001,  ( Emp02 - Emp01 ) / ( 0.5 * ( Emp02 + Emp01 ) ) as delEmp2002,  ( Emp03 - Emp02 ) / ( 0.5 * ( Emp03 + Emp02 ) ) as delEmp2003,  ( Emp04 - Emp03 ) / ( 0.5 * ( Emp04 + Emp03 ) ) as delEmp2004,  ( Emp05 - Emp04 ) / ( 0.5 * ( Emp05 + Emp04 ) ) as delEmp2005,  ( Emp06 - Emp05 ) / ( 0.5 * ( Emp06 + Emp05 ) ) as delEmp2006,  ( Emp07 - Emp06 ) / ( 0.5 * ( Emp07 + Emp06 ) ) as delEmp2007,  ( Emp08 - Emp07 ) / ( 0.5 * ( Emp08 + Emp07 ) ) as delEmp2008,  ( Emp09 - Emp08 ) / ( 0.5 * ( Emp09 + Emp08 ) ) as delEmp2009,  ( Emp11 - Emp10 ) / ( 0.5 * ( Emp11 + Emp10 ) ) as delEmp2011,  ( Emp12 - Emp11 ) / ( 0.5 * ( Emp12 + Emp11 ) ) as delEmp2012,  ( Emp13 - Emp12 ) / ( 0.5 * ( Emp13 + Emp12 ) ) as delEmp2013,  FROM `EMP`