Php word frequency tool PART 1

Hello, I need a php script that will do the following, 1, import a csv file like this: keyword,cost,sales,ctr,income petit chat vert,2.5,1,2.3,100 chat,10,2,1,20 grand chien,5,4,2.2,50 2) The script will compile data for EACH INVIDUAL WORD and make the sum and add a column with the number of time a word have been counted. petit,2.5,1,2.3,100,1 chat,12.5,3,3.3,120,2 <--- (2.5 + 10), (1+2), (2.3 + 1), (100 + 20), (chat appear 2 times in the list) vert,2.5,1,2.3,100,1 grand,5,4,2.2,50,1 chien,5,4,2.2,50,1 3) You must divide column CTR by the new column you created at step 2 and create a new column: petit,2.5,1,2.3,100,1,2.3 chat,12.5,3,3.3,120,2,1.65 <--- (3.3 / 2 = 1.65) vert,2.5,1,2.3,100,1,2.3 grand,5,4,2.2,50,1,2.2 chien,5,4,2.2,50,1,2.2 Must be well optimized ! Could contain 10 000+ lines !