plugin generated value does not disappeared during deactivation

I am new in plugin development, want to learn this. I created a plugin with the help of http://codex.wordpress.org/Creating_Options_Pages

<?php

/*
Plugin Name: 1pluginframework
Plugin URI:
Description: Custom plugin for lendingbig website.
Version: 1.0
Author: Jahur Ahmed
Author URI:
License: GPLv2 or later
*/

// create custom plugin settings menu
add_action('admin_menu', 'baw_create_menu');

function baw_create_menu() {

	//create new top-level menu
	add_menu_page('BAW Plugin Settings', 'BAW Settings', 'administrator', __FILE__, 'baw_settings_page',plugins_url('/images/icon.png', __FILE__));

	//call register settings function
	add_action( 'admin_init', 'register_mysettings' );
}

function register_mysettings() {
	//register our settings
	register_setting( 'baw-settings-group', 'new_option_name' );
	register_setting( 'baw-settings-group', 'some_other_option' );
	register_setting( 'baw-settings-group', 'option_etc' );
}

function baw_settings_page() {
?>
<div class="wrap">
<h2>Your Plugin Name</h2>

<form method="post" action="options.php">
    <?php settings_fields( 'baw-settings-group' ); ?>
    <?php do_settings_sections( 'baw-settings-group' ); ?>
    <table class="form-table">
        <tr valign="top">
        <th scope="row">New Option Name</th>
        <td><input type="text" name="new_option_name" value="<?php echo get_option('new_option_name'); ?>" /></td>
        </tr>

        <tr valign="top">
        <th scope="row">Some Other Option</th>
        <td><input type="text" name="some_other_option" value="<?php echo get_option('some_other_option'); ?>" /></td>
        </tr>

        <tr valign="top">
        <th scope="row">Options, Etc.</th>
        <td><input type="text" name="option_etc" value="<?php echo get_option('option_etc'); ?>" /></td>
        </tr>
    </table>

    <?php submit_button(); ?>

</form>
</div>
<?php echo get_option('new_option_name'); ?>
<?php } ?>

I put this code in theme’s header.php
<?php echo get_option('new_option_name'); ?>

When I deactivate this plugin, the value of <?php echo get_option('new_option_name'); ?> is not disappeared. How do I get proper plugin behavior.

Any suggestion is highly appreciated.

Thanks in advance to all.