How to finalize Woocommerce progressive discount?

Question

WordPress

Now the progressive discount from 30,000 rubles is 2%, from 100,000 = 4%, how to add a 3% discount with an amount from 60,000 to 10,000?

add_action('woocommerce_cart_calculate_fees','cart_price_progressive_discount'); 
function cart_price_progressive_discount() { 

    if (is_admin() && ! defined('DOING_AJAX')) 
     return; 

    $has_discount = false; 
    $stotal_ext = WC()->cart->subtotal_ex_tax; 

    // Discount percent based on cart amount conditions 
    if($stotal_ext >= 30000 && $stotal_ext < 100000 ) { 
     $percent = -0.02; 
     $percent_text = ' 2%'; 
     $has_discount =true; 
    } elseif($stotal_ext >= 100000 ) { 
     $percent = -0.04; 
     $percent_text = ' 4%'; 
     $has_discount =true; 
    } 
    // Calculation 
    $discount = $stotal_ext * $percent; 

    // Displayed text 
    $discount_text = __('Ваша скидка', 'woocommerce') . $percent_text; 

    if($has_discount) { 
     WC()->cart->add_fee($discount_text, $discount, false); 
    } 
    // Last argument in add fee method enable tax on calculation if "true" 
}