Horizontal analysis uses what formula to evaluate change from year to year?

$($New$$Old$)/$Newradio button unchecked$1$ of $4($New$$Old$)/$Oldradio button unchecked$2$ of $4($Old$$New$)/$Newradio button unchecked$3$ of $4($Old$$New$)/$Oldradio button unchecked$4$ of $4$