traceroute - 10.* and 172.30.* - where am I really?

First addresses for a tracert is 10.* and 172.30.*

I know these are reserved private address.

For 10., where am I ?
Am I alone in the modem ? Or am I IN my ISP router with every ISP customers having a different 10. address ? Or do every customer use the same 10.* address.

And if 10.* is only me and the home modem, does 172.* is the bigger ISP network ?