XML : Maxrows in rrdtool xport

I would like to export my rrd with all data from the last year with a 10 minute step between. My rrd file is updated every 1 minute with data. This is my code to xport:

  rrdtool xport --start now-1y --end now --step 600 --maxrows 219000 \         DEF:AverageIn="values.rrd":in:AVERAGE \         DEF:AverageOut="values.rrd":out:AVERAGE \         XPORT:AverageIn:'RX verdi' \         XPORT:AverageOut:'TX verdi' > exported.xml";    

After reading the documentation i needed to set --maxrows to make this happen because the default maxrow is 300(5 mins). My calculation of the maxrow: 600 sec(10 min) * 365 days(the last 1 year i wanted) = 219000

But this is my resulting xml:

  <xport>    <meta>      <start>1421331840</start>      <step>17280</step>      <end>1452850560</end>      <rows>1825</rows>      <columns>2</columns>      <legend>        <entry>RX verdi</entry>        <entry>TX verdi</entry>      </legend>    </meta>    <data>      <row><t>1421331840</t><v>NaN</v><v>NaN</v></row>      <row><t>1421349120</t><v>NaN</v><v>NaN</v></row>    

My rrdtool create code:

  rrdtool create $rrdsignal --step 60 --start now \              DS:in:GAUGE:600:U:U \              DS:out:GAUGE:600:U:U \              RRA:AVERAGE:0.5:1:2880 \              RRA:AVERAGE:0.5:1:2880 \              RRA:AVERAGE:0.5:6:700 \              RRA:AVERAGE:0.5:6:700 \              RRA:AVERAGE:0.5:24:775 \              RRA:AVERAGE:0.5:144:1500 \              RRA:AVERAGE:0.5:288:2000 \              RRA:MIN:0.5:1:600 \              RRA:MIN:0.5:6:700 \              RRA:MIN:0.5:24:775 \              RRA:MIN:0.5:144:1500 \              RRA:MIN:0.5:288:2000 \              RRA:MAX:0.5:6:700 \              RRA:MAX:0.5:24:775 \              RRA:MAX:0.5:144:1500 \              RRA:MAX:0.5:288:2000"    

How can I decrease the steps and increase the rows in this example? Please comment if something was unclear.

EDIT: Added rrd create code