All oil and gas leases issued pursuant to this chapter shall be upon a royalty of not less than twelve and one-half percent of the gross production of all oil, gas or other hydrocarbons produced and saved from the lands covered by such lease.
[ 1955 c 131 § 7. Prior: 1937 c 161 § 9; 1927 c 255 § 176. Formerly RCW 78.28.340.]