Scroll down

I have this jquery that does scroll animation when you click on a link.

How do I click the link, the scroll will go a little further down, type a 10% down, would it have?

// Smooth scroll function

$(document).on('click', '.menu-item a ,  #menu-one-page-menu a ', function (e) {
    if ($(e.target).is('a[href*="#"]:not([href="#"]')) {
        if (location.pathname.replace(/^\//, '') == this.pathname.replace(/^\//, '')
            || location.hostname == this.hostname) {
            var target = $(this.hash);
            target = target.length ? target : $('[name=' + this.hash.slice(1) + ']');
            if (target.length) {
                $('html,body').animate({
                    scrollTop: target.offset().top

                }, 1000);
                return false;
            }
        }
    }
});