JSFiddle - React, Tailwind, and code Playground

JavaScript

/**
         * count the values from a set of key value pairs and count the occurrences of each value
         * @param {object} input - an object containing key value pairs
         * @throws {error} TypeError - if <tt>input</tt> is not an object
         * @return {object} counts - an object keying the number of times each value occurs
         */
        var value_count = function (input) {
            if (Object.prototype.toString.call(input) === '[object Object]') { 
            var counts, key, val;
            console.log(input);
            counts = {};
            for (key in input) {
                val = input[key];
                if (input.hasOwnProperty(key)) {
                    if (counts.hasOwnProperty(val)) {
                        counts[val] += 1;
                    } else {
                        counts[val] = 1;
                    }
                }
            }
            return counts; 
            } else { 
                throw new TypeError('expected input to be an Object');
            }

        };

        //input
        var input = {
            DoctorD: "N",
            DoctorE: "N",
            DoctorF: "N",
            DoctorG: "N",
            DoctorH: "N",
            DoctorI: "N",
            DoctorJ: "N",
            DoctorK: "N",
            DoctorL: "N",
            DoctorM: "N",
            DoctorN: "N",
            DoctorO: "N",
            DoctorP: "N",
            DoctorQ: "N",
            DoctorR: "N",
            DoctorS: "N",
            DoctorT: "N",
            DoctorU: "N",
            DoctorV: "Y",
            DoctorW: "N",
            DoctorX: "N",
            DoctorY: "N",
            DoctorZ: "N",
            DoctorAA: "N",
            DoctorAB: "N",
            DoctorAC: "N",
            DoctorAE: "N",
            DoctorAF: "N",
            DoctorAG: "N",
            DoctorAH: "N",
            DoctorAI: "N",
            DoctorAJ: "N",
            DoctorAK: "N",
            DoctorAL: "N",
           ...