19.

Leases

The following table shows the composition of our lease revenue:

	Three Months Ended March 31,
(In thousands)	2015		2014
Base rent (straight-line)	$	29,372	$	24,837
Percentage rent		—		—
Total lease revenue	$	29,372	$	24,837

SDTS, SDTS FERC and SPLLC have entered into various leases with Sharyland and SU FERC for all of our placed in service T&D assets. The master lease agreements, as amended, expire at various dates from December 31, 2015 through December 31, 2022. Each agreement includes annual base rent while all but one agreement includes additional percentage rent (based on an agreed upon percentage of the gross revenue of Sharyland, as defined in the lease agreements, in excess of annual specified breakpoints, which decrease over the term of the agreements). The rate used for percentage rent varies by lease and ranges from a high of 37% to a low of 23% over the term of the agreements. Percentage rent was not recognized during the three months ended March 31, 2015 and 2014 as Sharyland’s revenue had not exceeded the annual specified breakpoints. Because an annual specified breakpoint must be met under our leases before we can recognize any percentage rent, we anticipate our revenue will grow over the year with little to no percentage rent recognized in the first quarter each year with the largest amounts recognized during the third and fourth quarters of each year.