Maperitive: show less housenumbers or only divisible by 10 (e.g. 10, 20, 30,…)

I want to show addr:housenumber on zoom level 16 but for some cities (like Berlin) the street names are covered by house numbers. It looks ok in Maperitive, but if use "generate-tiles", the numbers are cluttered together.

My question is: how can I show "less" house numbers?

I posted the rule below. I played aroud with placement-value and halo-width, but with no success. The worst actually: the house numbers are rendered above the street names. Even if that wasn't the case, the tiles would work for me.

Another idea was to use regex to only show numbers which end with a "0" - i.e. are divisible by 10.

There is a little documentation about this under feature selector: http://maperitive.net/docs/Feature_Selectors.html. But I don't know how I could parse the value of addr:housenumber through regex.

Any ideas? Thanks, micz

P.S. here some more info and the rules:

http://stackoverflow.com/questions/12403842/check-number-divisibility-with-regular-expressions

target : housenumber
    define
        min-zoom : 16
        text : [[addr:housenumber]]
        text-halo-width : 0
        text-color: #666666
        font-weight: normal
        font-size : 13
        placement-value : 0.01
    draw : text