send a certain portion to a specific address with every transaction in Smart Contract

i have created a Smartcontract. now i want the functionality: where 2.5% of every transaction is transferred to a fixed address. say the address is 0x809341c1c1cba2d6accf8188bca463a119443d. i know it can be done but could not able to sum up the code.

here is the contract

 `pragma solidity ^0.5.0;


 contract ERC20Interface {
      function totalSupply() public view returns (uint);
     function balanceOf(address tokenOwner) public view returns (uint balance);

function allowance(address tokenOwner, address spender) public view returns (uint remaining);

function transfer(address to, uint tokens) public returns (bool success);

function approve(address spender, uint tokens) public returns(bool success);

function transferFrom(address from, address to, uint tokens) public returns (bool success);

event Transfer(address indexed from, address indexed to, uint tokens);
event Approval(address indexed tokenOwner, address indexed spender, uint tokens);

}

safe math---------------------------------------------------------------------------
......................
/////////

contract me is ERC20Interface, SafeMath {
string public name;
string public symbol;
uint8 public decimals; // 18 decimals is the strongly suggested default, avoid changing it

uint256 public _totalSupply;

mapping(address => uint) balances;
mapping(address => mapping(address => uint)) allowed;


constructor() public {
    name = "me";
    symbol = "me";
    decimals = 18;
    _totalSupply = 250000000000000000000000000;

    balances[msg.sender] = _totalSupply;
    emit Transfer(address(0), msg.sender, _totalSupply);
}

function totalSupply() public view returns (uint) {
    return _totalSupply  - balances[address(0)];
}

function balanceOf(address tokenOwner) public view returns (uint balance) {
    return balances[tokenOwner];
}

function allowance(address tokenOwner, address spender) public view returns (uint remaining) {
    return allowed[tokenOwner][spender];
}

function approve(address spender, uint tokens) public returns (bool success) {
allowed[msg.sender][spender] = tokens;
emit Approval(msg.sender, spender, tokens);
return true;
}

function transfer(address to, uint tokens) public returns (bool success) {
    balances[msg.sender] = safeSub(balances[msg.sender], tokens);
    balances[to] = safeAdd(balances[to], tokens);
    emit Transfer(msg.sender, to, tokens);
    return true;
}

function transferFrom(address from, address to, uint tokens) public returns (bool success) {
    balances[from] = safeSub(balances[from], tokens);
    allowed[from][msg.sender] = safeSub(allowed[from][msg.sender], tokens);
    balances[to] = safeAdd(balances[to], tokens);
    emit Transfer(from, to, tokens);
    return true;
}

}