CNNMoney says although existing home sales increased 3.7 percent in March over February, sales were down 6.3 percent from March 2010.  Compared to a year ago, the median home price fell 5.9 percent.  New home construction permits increased slightly in March, but according to the National Association of Realtors (NAR), the average credit score for a conventional mortgage increased to 760 points from 720 in 2007, making financing still difficult to find.  All-cash sales accounted for 35 percent of March home sales, a record high.  The numbers are in line with economists who predicted five million homes will be sold this year.