Hello everyone, hope you all have a good day ahead.

So i want to ask 1 question.. i have a data set which consist of ID, Year, Dummy_rich.

Year ID rich
2005 1101 0
2006 1101 0
2007 1101 1
2008 1101 0
2009 1101 0
2010 1101 1
2011 1101 1
2012 1101 0
2013 1101 1
2005 1102 0
2006 1102 0
2007 1102 0
2008 1102 0
2009 1102 1
2010 1102 1
2011 1102 0
2012 1102 1
2013 1102 2
2005 1103 1
2006 1103 0
2007 1103 1
2008 1103 1
2009 1103 0
2010 1103 3
2011 1103 1

Then i want to create one other variable which formed by the calculation of sum dummy_rich, but in different way. i don't know what is the name of this form. here it is

Year ID rich sum_rich
2005 1101 0 0
2006 1101 0 0
2007 1101 1 1
2008 1101 0 1
2009 1101 0 1
2010 1101 1 2
2011 1101 1 3
2012 1101 0 3
2013 1101 1 4
2005 1102 0 0
2006 1102 0 0
2007 1102 0 0
2008 1102 0 0
2009 1102 1 1
2010 1102 1 2
2011 1102 0 2
2012 1102 1 3
2013 1102 2 5
2005 1103 1 1
2006 1103 0 1
2007 1103 1 2
2008 1103 1 3
2009 1103 0 3
2010 1103 3 6
2011 1103 1 7

Do you guys could help me to find out what is the name of this form and the syntax which i could use in stata? Thank you so much.

ohya Fyi, i already tried several syntax such as egen count, egen sum, egen total, gen _n and so on..