That's a pretty broad scope there.
Commercial ops range from scenic flights in a C206 to long haul 744's and every thing in between and around.
Also, each country has different wages/tax rates/cost of living too.
eg. In Oz, single engine VFR charter flying I was earning ~$A20K in 1994, 1995 twin engine VFR ~$A25K. Twin engine IFR $32K.
1999, FO on Bandits/Twotters, $A32K (after a pay rise). Dash 8 FO ~$A45K.
Sorry they are rough gross salaries. I haven't included allowances/expenses/tax deductions in there either. For the Dash 8 ops, I was expecting to get about ~$A3-5K's worth.
In the UK. FO on a Shed (Shorts 360) flying night freight is £16K + allowances. (~£2-3K)
SFO on a lo co 737 operation £35-39K plus allowances. (~£3-5K)