HC-110 Dilution E: Confused about how much developer to use

I would like to use Dilution E with my Tri-X exposed at 400. Dilution E is explained at the Covington site as follows:

Dilution SYRUP |
1rl steel tank 240ml |
1rl plastic tank 300ml |
2rls steel tank 480ml |
2rls plastic tank 600ml |

E (1:47) |
5 mL |
6.3mL |
10mL |
12.5mL |

I have a __steel__ Kindermann __5-roll__ tank which holds (with spirals submerged, which is how I assume I should measure) 1030ml. Approximately how much HC-110 should I use when developing five rolls in this tank using Dilution E?

Edit (to prevent people thinking I'm totally mathematically inept): I would have thought it would be a total of 21ml for five rolls but the reason for my question is I read somewhere that one needs 6ml per roll which the above doesn't work out to be.

Many thanks for your help

Philip