iterating through hash of lists in javascript

hashList.js

data = {
    subject: ['Medical Science', 'Philosophy'],
    year: ['2015', '2013']
};

for (key in data) {
    if (data.hasOwnProperty(key) && data[key] instanceof Array) {
        list = data[key];
        list.forEach(function (value) {
            console.log(key + " : " + value);
        });

    }
}