AD5781 Readback mode


Please let me know about minimum SCLK cycle time of  AD5781 at readaback mode.

Datasheet says below at table4 timing characteristics.

t1 = 28 ns min : SCLK cycle time

t1= 60 ns min: SCLK cycle time (readback mode)

In attached  readback mode timing diagrame of AD5781,

which Is minimum SCLK cycle time at first 24 sclk cycle (red circle)  28ns or 60ns ?