How we store shipping rates per product

shippingrates.php

<?php 

for ( $i = 0; $i < $shipping_fee_count; $i ++ ) { 
    if ( $shipping_fees[ $i ] != '' ) { 
        $country = wc_clean( $shipping_countries[ $i ] ); 
        $state = wc_clean( $shipping_states[ $i ] ); 
        $fee = wc_format_decimal( $shipping_fees[ $i ] ); 
        $shipping_rates[ $i ] = array( 
          'country'	=> $country,
          'state' => $state,
          'fee' => $fee,
        );
    }
}

update_post_meta( $product_id, ‘_wcv_shipping_rates’, $shipping_rates );