 Only the latitude range between 37 to 57 in each hemisphere remains stable over the period, and therefore, those bands are called the permanent tropical arctic zones on Pluto (which covers 20\% of the total area).
<meaning-changed>  Only the latitude range between 37 to 57 in each hemisphere remains stable over the period, and therefore, those bands are called the permanent tropical arctic zones on Pluto (which covers 20\% of the total area).
 Only the latitude range between 37 to 53 in each hemisphere remains stable over the period, and therefore, those bands are called the permanent tropical arctic zones on Pluto (which covers 20\% of the total area).