wavel.	cross section	error limit

270	2.50e-20	1.3e-21
275	2.08e-20	1.0e-21
280	1.67e-20	8.0e-22
285	1.27e-20	6.0e-22
290	9.05e-21	4.5e-22
295	5.84e-21	2.9e-22
300	3.77e-21	1.9e-22
305	2.26e-21	1.1e-22
310	1.28e-21	6.0e-23
315	6.7e-22		4.0e-23
320	3.2e-22		2.0e-23
325	1.5e-22		1.0e-23
330	6.4e-23		5.0e-24
335	2.7e-23		4.0e-24
340	1.1e-23		3.0e-24
345	4.5e-24		2.4e-24