JavaScript&JQ 合併table中td下相同的數據

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<table border="1px;" id="subtable">
    		<tr>
    			<td>1</td>
    			<td>2</td>
    			<td>3</td>
    		</tr>
    		<tr>
    			<td>1</td>
    			<td>2</td>
    			<td>5</td>
    		</tr>
    		<tr>
    			<td>1</td>
    			<td>6</td>
    			<td>7</td>
    		</tr>
    		<tr>
    			<td>2</td>
    			<td>8</td>
    			<td>9</td>
    		</tr>
    		<tr>
    			<td>2</td>
    			<td>8</td>
    			<td>9</td>
    		</tr>
    		<tr>
    			<td>3</td>
    			<td>8</td>
    			<td>9</td>
    		</tr>
    		<tr>
    			<td>4</td>
    			<td>8</td>
    			<td>9</td>
    		</tr>
    		
    	</table>