In iostat, why are kB_wrtn/s and kB_wrtn the same?

/dev/sdc is a SATA hard drive. Do the kB_read and kB_wrtn fields sometimes, in some situations, show total counts? Here it seems to be just the same as the per second value. - Linux kernel 5.4.0-26-generic. - sysstat version 12.2.0 iostat -dz 1

Device             tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
sdc              40.00         0.00        21.00         0.00          0         21          0


Device             tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
dm-0              6.00         0.00        24.00         0.00          0         24          0
sdc              42.00         0.00        42.50         0.00          0         42          0


Device             tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
dm-0              5.00         0.00        20.00         0.00          0         20          0
sdc              43.00         0.00        36.00         0.00          0         36          0


Device             tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
sdc              48.00         0.00        25.00         0.00          0         25          0


Device             tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
sdc              36.00         0.00        18.50         0.00          0         18          0


Device             tps    kB_read/s    kB_wrtn/s    kB_dscd/s    kB_read    kB_wrtn    kB_dscd
sdc              40.00         0.00        21.00         0.00          0         21          0