JSFiddle - React, Tailwind, and code Playground

JavaScript

var v={

		"2015-09-23":[
			{"AllConversions":"0.1","AverageCpc":"0.01","AverageCpm":"0.02","AveragePosition":"8.3",Id:1},    
			{"AllConversions":"0.0","AverageCpc":"0.00","AverageCpm":"0.00","AveragePosition":"9.0",Id:1}
		],

		"2015-09-18":[
			{"AllConversions":"0.1","AverageCpc":"77.14","AverageCpm":"239.57","AveragePosition":"7.7",Id:1},
			{"AllConversions":"0.0","AverageCpc":"39.97","AverageCpm":"703.91","AveragePosition":"3.8",Id:1},   

			{"AllConversions":"0.0","AverageCpc":"20.40","AverageCpm":"381.36","AveragePosition":"4.3",Id:1}

		]};


		var columns=[
		"AllConversions","AverageCpc","AverageCpm","AveragePosition"
		];

	var output = {};
	var smallOutput = {};
	var tempDate = [];
		for(var i in v){
			var temp = 0;
			for(var j = 0; j < columns.length ; j++){
				for(var k = 0 ; k < v[i].length; k++)	temp += parseFloat(v[i][k][columns[j]]);

				smallOutput[columns[j]] = temp ;
				temp=0;
			
			}
			output[[i]] = smallOutput;
		}

		console.log(output);