This may be faster:

    e=>sub{
                $wait *= $wait > 0;
                $wait = -34;
                },
[download]

For negative numbers:

        Rate    d    b    a    c    e
d  7216838/s   --  -7% -13% -16% -35%
b  7785170/s   8%   --  -6% -10% -30%
a  8270205/s  15%   6%   --  -4% -26%
c  8609980/s  19%  11%   4%   -- -23%
e 11128061/s  54%  43%  35%  29%   --
[download]

For positive numbers:

        Rate    a    d    e    c    b
a  9665991/s   -- -10% -14% -24% -26%
d 10777285/s  11%   --  -4% -15% -17%
e 11190507/s  16%   4%   -- -12% -14%
c 12748698/s  32%  18%  14%   --  -2%
b 13022958/s  35%  21%  16%   2%   --
[download]