When 720 is the t c (°c) what is the   h ci (ka/m)?
CREATE TABLE "magnetic_properties" (
  "magnet" text,
  "b_r_t" text,
  "h_ci_k_a_m" text,
  "bh_max_k_j_m_3" text,
  "t_c_c" text
);
SELECT "h_ci_k_a_m" FROM "magnetic_properties" WHERE "t_c_c"='720';