remove lines with awk when the value is smaller than
<p>Hello I have this input:</p>

<pre><code>10579 5 2.0 5 100 0 20 0 80 0 20 0.72 
10586 5 2.0 5 100 0 20 0 40 20 40 1.52
10856 4 3.2 4 100 0 26 0 69 30 0 0.89
11049 6 12.2 6 65 26 48 14 36 49 0 1.43
11041 2 26.0 2 70 37 20 8 43 47 0 1.34
11012 5 3.0 5 90 9 25 0 56 43 0 0.99
11041 5 3.0 5   9 25 0 56 43 0 0.99
11096 6 2.2 6 100 0 26 15 30 53 0 1.42
11194 1 28.0 1 93 6 51 0 3 96 0 0.22
11236 5 2.4 5   0 24 0 41 58 0 0.98
11981 1 10.0 1 50 18 15 0 9 0 90 0.44
12184 5 2.2 5 100 0 22 18 0 54 27 1.44
12482 4 2.5 4 100 0 20 20 0 80 0 0.72
12627 5 2.2 5 100 0 22 18 0 81 0 0.68
</code></pre>

<p>I want to remove lines when the column 5 is smaller than 85. I can do that with awk (<code>awk '$5 &gt; 85'</code>) but I want to keep lines when $5 is empty (line 7 and 10). So my output will be like this:</p>

<pre><code>10579 5 2.0 5 100 0 20 0 80 0 20 0.72 
10586 5 2.0 5 100 0 20 0 40 20 40 1.52
10579 5 2.0 5 100 0 20 0 80 0 20 0.72 
10586 5 2.0 5 100 0 20 0 40 20 40 1.52
10856 4 3.2 4 100 0 26 0 69 30 0 0.89
11012 5 3.0 5 90 9 25 0 56 43 0 0.99
11041 5 3.0 5   9 25 0 56 43 0 0.99
11096 6 2.2 6 100 0 26 15 30 53 0 1.42
11194 1 28.0 1 93 6 51 0 3 96 0 0.22
11236 5 2.4 5   0 24 0 41 58 0 0.78
12184 5 2.2 5 100 0 22 18 0 54 27 1.44
12482 4 2.5 4 100 0 20 20 0 80 0 0.72
12627 5 2.2 5 100 0 22 18 0 81 0 0.68
</code></pre>

<p><code>awk '$5 &gt; 85'</code> is removing also those line. Any help? Thanks</p>