title: how to get top rows from particular approx. percentage using sql server 2008?
body: <p>i need approx. 30 percentage data from each date.</p>
  
  <pre><code>id     name   datecol
  -----------------------
  1       A     2016-11-11
  2       B     2016-11-11
  3       C     2016-11-11
  4       D     2016-11-11
  5       E     2016-11-11
  6       F     2016-11-11
  7       G     2016-11-11
  8       H     2016-11-11
  9       I     2016-11-11
  10      J     2016-11-11
  11      A1    2016-11-12
  12      B1    2016-11-12
  13      C1    2016-11-12
  14      D1    2016-11-13
  15      E1    2016-11-13
  16      F1    2016-11-14
  17      G1    2016-11-14
  18      H1    2016-11-14
  19      I1    2016-11-14
  20      J1    2016-11-14
  </code></pre>
  
  <blockquote>
    <p>In this case i have</p>
  </blockquote>
  
  <p>10 rows in 2016-11-11<br>3 rows in 2016-11-12<br>2 rows in 2016-11-13<br>
  5 rows in 2016-11-14</p>
  
  <blockquote>
    <p>i need like this by approx. 30 percentage of top rows from each date,</p>
  </blockquote>
  
  <pre><code>id     name   datecol
  -----------------------
  1       A     2016-11-11
  2       B     2016-11-11
  3       C     2016-11-11
  11      A1    2016-11-12
  14      D1    2016-11-13
  16      F1    2016-11-14
  17      G1    2016-11-14
  </code></pre>
  
  <p>Thanks in Advance.</p>