Pivoting data in data flows (Year over year || week over week)

Hi,

I have account information on one of my data sets like this:

Registrations:

Name  Date_of_Registration  
Daniel    2015-12-01
John      2015-10-22
Peter     2014-12-01

I want to use dataflows in order to pivot this data in two ways:

#1 New registrations per year

2014   2015  
 1     2     

#2 New registrations per week

Week      2014     2015
10          0        1
12          1        1

To solve this I've used a mysql that does this (mysql doesn't have a pivot function):

select  
sum(case when YEAR (date_of_registration) = 2014 then 1 else 0 end ) Year_2014
sum(case when YEAR (date_of_registration) = 2015 then 1 else 0 end )  Year_2015
from registrations

this works fine for yearly data, however for weekly data I was planning to do something like this:

select
sum(case when WEEK (registration_date) = 30 AND YEAR (registration_date) = 2014 then 1 else 0 end ) Week30_Year2014
sum(case when WEEK (registration_date) = 30 AND YEAR (registration_date) = 2015 then 1 else 0 end ) Week30_Year2015
from registrations

The query above would be fine for showing only two specific weeks, however I would like to have 2010 to 2015 and I don't want to add a sum per week per year.

Is there a better way to do this? Any help is grealy appreciated.