PHP function to calculate results

Please create a php function that returns an array with the X% value for the lowest and the X% value from the highest value for each month and day. The data is in the format: id,year,month,day,element,value. Discard any value that is not numeric from your calculation, ex - -6T. See attached csv file for data to test against (93051 lines). Be willing to demonstrate results on your server before final payment by including a textarea field where I can drop data into (see format below and in the attached csv file). I will want to test against a small sample size, less than 100 rows of data. function X_value ($data, $element, $percent) { // do something } $results = X_value($data, "TMIN", 90); print_r($results); [USC00101017] => Array ( [01] => Array ( [1] => Array ( [TMIN] => Array ( [90] => Array ( [min] => -6 [max] => 72 ) ) ) [2] => Array ( [TMIN] => Array ( [90] => Array ( [min] => // some number [max] => // some number ) ) ) ... ) [02] => Array ( [1] => Array ( [TMIN] => Array ( [90] => Array ( [min] => // some number [max] => // some number ) ) ) [2] => Array ( [TMIN] => Array ( [90] => Array ( [min] => // some number [max] => // some number ) ) ) ... ) ... ) ex - 90% (min) for TMIN for May 1 is -22, 90% (max) for TMIN for May 1 is 72 USC00101017,2013,05,1,TMIN,-56 USC00101017,2008,05,1,TMIN,-33 USC00101017,2011,05,1,TMIN,-22 << 90% (min) USC00101017,1997,05,1,TMIN,-6 USC00101017,2010,05,1,TMIN,-6 USC00101017,2009,05,1,TMIN,0 USC00101017,2001,05,1,TMIN,6 USC00101017,2012,05,1,TMIN,17 USC00101017,2003,05,1,TMIN,28 USC00101017,2006,05,1,TMIN,28 USC00101017,2015,05,1,TMIN,28 USC00101017,2016,05,1,TMIN,28 USC00101017,2002,05,1,TMIN,44 USC00101017,2005,05,1,TMIN,44 USC00101017,1999,05,1,TMIN,56 USC00101017,2004,05,1,TMIN,56 USC00101017,2014,05,1,TMIN,56 USC00101017,2000,05,1,TMIN,72 << 90% (max) USC00101017,2007,05,1,TMIN,83 USC00101017,1998,05,1,TMIN,94 In your proposal here or through private message, let me know how you will handle calculating the 90% level when there are 5 values to work with, ex - 1,3,7,7,13 ... what value would you use for the 90% min and max?