MySQL Group by conditioning

Is there a way to only group by certain rows when a specific value is set?

i.e. I have the following table:

USERNO  |   FIRSTNAME   |   NAME    |   CUSTOMER    |   YEAR
1       |   Jon         |   Snow    |   0           |   2014
2       |   Williams    |   Spear   |   1           |   2015
1       |   John        |   Snow    |   1           |   2015
3       |   Sam         |   Wells   |   0           |   2014
3       |   Sam         |   Wells   |   0           |   2013

When CUSTOMER is 1, it should group by USERNO. So I want the following result:

USERNO  |   FIRSTNAME   |   NAME    |   CUSTOMER    |   YEAR
1       |   Jon         |   Snow    |   1           |   2014
2       |   Williams    |   Spear   |   1           |   2015
3       |   Sam         |   Wells   |   0           |   2014
3       |   Sam         |   Wells   |   0           |   2013

Is this possible?

Thanks in advance!